Time models, character motivations, Time Turner usage and time travel in other stories.
"You Must Not Be Seen!"
Time travel is a fascinating subject. The idea of travelling through time, to change the past, has always intrigued authors and readers alike. From H.G. Wells' Time Machine to Terminator, time travel has been at the core of many stories.
J.K. Rowling has used it too; in Harry Potter and the Prisoner of Azkaban, Harry and Hermione use a small time machine to travel three hours into the past in order to save Harry's godfather, Sirius Black, from the Dementor's Kiss.
In the film version of the book, Alfonso Cuaron and Steve Kloves went one step further and made time a central concept of the film. Repeatedly you see the giant clock of Hogwarts.
From the first time I read the book, I regarded Rowling's use of time travel as the most brilliant one I've ever seen. Everything fits together, there are no loose ends anywhere. Therefore, when I later joined the Harry Potter fandom, I was astounded to find that many people regarded the subject as confusing and contradictory. I believe it isn't, and resulting from the debates on the subject on the SugarQuill I've decided to write this essay to show these people a way to view the story so that there are no contradictions.
A short summary of the relevant scenes in PoA.
All year long, Harry has been hunted by Sirius Black. On the sidelines, Hermione has taken more classes than seems logically possible and Ron's rat, Scabbers, has gone missing, presumed dead.
Then comes the day when the Hippogriff Buckbeak is to be executed. The Trio goes down to Hagrid's hut to say goodbye to the animal. In the hut, they discover that Scabbers is still alive. Ron collects the rat and they leave before the executioner McNair, Fudge and Dumbledore arrive. From afar, they finally hear the fall of the executioner's axe and Hagrid's howl.
Meanwhile, Scabbers has repeatedly attempted to flee from Ron and finally manages it. He darts away, Ron after him. Suddenly a black dog appears and drags Ron into a secret tunnel. Harry and Hermione go after him and end up in the Shrieking Shack, where it turns out that the dog is really Sirius Black. After a short struggle, Harry has a chance to kill Black but doesn't, partly due to the arrival of Remus Lupin.
Remus discovers the truth about Sirius, but before they can explain, Severus Snape appears and wants to take both Remus and Sirius to the Dementors. Harry blocks the doorway, and in the struggle all three kids cast a simultaneous disarming spell on the teacher, knocking him out.
Then the truth comes to light. Not Sirius, but Peter Pettigrew betrayed Harry's parents. Pettigrew, who is an animagus too and has spent the last thirteen years in his rat form as Scabbers. They bind him and leave through the tunnel, floating the still unconscious Snape behind them.
But it is a full moon, and the werewolf Remus forgot to take his potion. He turns into a monster and Pettigrew escapes, knocking Ron unconscious in the process. Sirius manages to drive the werewolf away, but has to flee then himself. He's stopped by the Dementors. Harry and Hermione go after him, but are unable to defeat the mass of Dementors. Hermione passes out. All of them are in acute danger of losing their souls, when suddenly a corporal Patronus in stag form appears. It drives the Dementors away and returns to its owner. Just before passing out, Harry catches a glimpse of the owner and believes him to be his father, because of their physical similarity.
Harry wakes up in the hospital wing. After Snape woke up, he took all three children there. Sirius Black is locked up in Flitwick's office, awaiting the Dementor's Kiss. Harry and Hermione try to convince the adults present of Sirius' innocence, but they aren't believed by anyone except Dumbledore. He talks to them alone and tells them to use the Time Turner to save “two innocent souls.” Hermione takes out the Time Turner and uses it to bring the two of them three hours into the past.
After travelling, they realise that the second innocent soul they must save is Buckbeak's. They are to prevent his death and then use him to rescue Sirius. They settle down outside Hagrid's hut to wait for the executioner. He appears and checks on the Hippogriff, then goes back into the hut. Thanks to a delay provided by Dumbledore, the two kids are then able to free Buckbeak and disappear into the forest. When the executioner comes out again, he finds the Hippogriff gone. In his anger, he hits a fence with his axe while Hagrid howls with delight. Dumbledore discourages the search for the culprit. Harry and Hermione settle back to wait once more. They see themselves go into the tunnel and come out again.
Then Harry wants to see his father as he casts the Patronus. He creeps close to where he saw the figure, but no one appears, while the Dementors close on his past self. In the last moment he realises that he himself cast the Patronus, that he saw himself. Knowing that he can, that he already saw himself do it, he casts his Patronus, which drives away the Dementors. Then Snape appears and carries everyone away. Harry and Hermione use Buckbeak to fly to the office where Sirius is held and free him. Then they race back to the hospital wing and arrive just in time to settle back into bed before Snape and Fudge come in, the former livid that Sirius escaped and ready to accuse Harry of freeing him. Harry, however, was apparently locked up in the hospital wing all the time. Dumbledore points out to Snape that, unless he is “suggesting that Harry and Hermione are able to be in two places at once,” there is no point in accusing the two. And thus the matter is ended.
For reference, here are the time lines of the events of that evening, once from the point of view of an omniscient observer and once from the point of view of the travellers.
The following objective time line is derived from the one at the Harry Potter Lexicon, but is not a copy. Harry2 and Hermione2 reference the time travellers.
Harry, Ron, and Hermione go to Hagrid's. Harry2 and Hermione2 arrive from the future and hide in a cupboard. They all arrive about 10 minutes later.
Harry, Ron, and Hermione leave Hagrid. the committee arrives. Harry2 and Hermione2 are hidden near Hagrid's hut.
McNair looks out of Hagrid's window and sees Buckbeak. Directly afterwards, Harry2 and Hermione2 rescue Buckbeak. McNair and the others come out of the hut. Harry, Ron and Hermione believe he kills Buckbeak.
Scabbers struggles and finally escapes. The committee returns to Hagrid's hut. Harry2 and Hermione2 are hidden once again with Buckbeak.
Ron catches Scabbers. Sirius turns up as Snuffles and drags Ron into the Willow. Harry and Hermione follow him.
Committee back inside the school.
Lupin runs out of the front doors to the Willow.
Sirius, Ron and Peter arrive in the Shrieking Shack.
Snape arrives at the Willow, picks up the invisibility cloak, finds Lupin's stick and enters.
Crookshanks, Harry and Hermione arrive in the Shrieking Shack.
Harry, Hermione, Ron, Crookshanks and Sirius struggle. Harry manages to point a wand at Sirius.
Lupin arrives in the room. He stops Harry from killing Sirius and embraces his old friend. Hermione reveals that Lupin is a werewolf. Lupin settles down to explain everything. He tells about the Marauder's Map and that Scabbers is really Peter.
Snape comes in under the invisibility cloak. Lupin tells the Trio about the Animagi and about Snape's near death.
Snape takes off the cloak. He ties Lupin up and wants to take him and Sirius away. Harry blocks his way. The Trio knocks Snape out.
Sirius and Lupin expose Peter. Harry stops them from killing the traitor. They tie Peter up and leave.
Everyone leaves the Whomping Willow.
Lupin transforms. Sirius turns into a dog and they fight.
Harry2, Hermione2 and Buckbeak change the spot they wait in.
Lupin runs for the Forbidden Forest .
Sirius returns. Harry tells him that Peter escaped. Sirius flees.
Harry and Hermione hear Sirius' cries and run after him.
Harry and Hermione find Sirius and the Dementors. Harry2 has left his cover and watches events from the opposite side of the lake.
Harry and Hermione try to cast a Patronus. They fail. Hermione passes out.
Harry2 casts his Patronus. Harry sees the Patronus returning to Harry2 and believes Harry2 to be his father. Then he falls unconscious.
Harry2 and Hermione2 see Snape taking the people up to school.
Dumbledore, Snape and Sirius are in Flitwick's office.
Dumbledore talks to Sirius. Snape meets Fudge near the Hospital wing.
Harry and Hermione wake up. They overhear Snape and Fudge talking.
Dumbledore leaves Sirius. Madam Pomfrey notices that Harry is awake.
Dumbledore turns up at the Hospital wing and cuts off Harry's and Hermione's attempts at explaining the events.
Snape and Fudge send McNair to get the Dementors.
Harry2 and Hermione2 see McNair at the front of the school.
Harry2 and Hermione2 rescue Sirius.
Harry2 and Hermione2 start down the West Tower.
Snape and Fudge walk past Harry2 and Hermione2 and the West Tower, on their way to Flitwick's office.
Harry and Hermione leave the Hospital wing, Harry2 and Hermione2 arrive back at the Hospital wing.
The offsets in the following subjective time line are based on the times in the objective time line and are relative to 8:55 of the Harry that hasn't travelled yet.
Harry, Ron and Hermione go to Hagrid.
They hear the axe and Hagrid's howl.
Scabbers escapes. Ron runs after him. Sirius turns up and drags Ron into the Willow.
Harry and Hermione follow them into the Willow.
They arrive in the room where Ron is held. Sirius lies in wait and disarms them.
They struggle. Harry manages to get a wand. He points it at Sirius with the intention of killing him, but cannot bring himself to do it.
Lupin arrives and disarms Harry. They accuse him of helping Sirius. Lupin begins to explain. During the explanation, the door moves, but they see nothing.
Snape appears from under the cloak. He binds Lupin and prepares to leave. Harry blocks the door. Harry, Ron and Hermione knock Snape out.
Sirius and Lupin force Peter to transform. They decide to kill him, but Harry steps in. They tie Peter up and put a splint on Ron's leg.
Lupin transforms. Sirius does, too, and they fight. Eventually Lupin flees.
During the fight, Peter grabs Lupin's wand, knocks Ron out, transforms and flees.
Sirius chases after Peter, but is soon intercepted by Dementors.
Harry and Hermione go after Sirius and find him unconscious, surrounded by Dementors. They try in vain to conjure a Patronus.
Hermione passes out. Harry is close to passing out, too, when suddenly a stag Patronus appears. It drives the Dementors away and then returns to its owner, who Harry believes to be his father. Harry then passes out.
Harry and Hermione wake up in the hospital wing. They see Snape and Fudge and begin to argue that Sirius is innocent. They are not believed.
Dumbledore turns up in the hospital wing. He eventually sends everyone out and tells Harry and Hermione to use the Time Turner.
Harry and Hermione use the Time Turner.
They appear three hours earlier in the entrance hall and hide. Hermione explains to Harry about the Time Turner.
They hide from the committee behind a tree near Hagrid's hut.
After McNair has checked on Beaky, Harry and Hermione free him and hide again.
They watch as the committee comes out and McNair hits the fence with his axe in anger. Then they settle down to wait. Harry repeatedly wants to take action, but Hermione prevents it. Harry tells Hermione about how he saw his father.
They watch themselves come out of the Willow.
Harry realises that Lupin will run straight for them. They flee to Hagrid's hut.
Harry wants to see his father and walks to where he saw him.
He watches as the Dementors attack. He waits in vain for his father.
He realizes it was him who cast the Patronus and does so.
Hermione catches up to Harry. Together they watch Snape.
They see McNair come out of the school and mount Beaky. They fly Flitwick's office and rescue Sirius. They fly on to the West Tower, where they say goodbye.
After having avoided Snape and Fudge and outwaited Peeves, they arrive back at the Hospital Wing. Dumbledore locks them in and they crawl back into their beds.
So far the facts. Everything fits perfectly together, like a puzzle.
But therein lies the difficulty for some people. How can Harry go back in time to save himself? In the normal flow of events (i.e. without time travel), Harry loses his soul to the Dementors. How, then, can he go back in time to save himself?
This is a basic misunderstanding of the way time works in the story. So let's review some models of time. All names are invented by me.
The open single flow model is the easiest when there is no time travel, but the most complicated when there is. In the OSF model there is a single thread of time which is spun along as people make decisions. The model offers completely free will. The existence of definite prophecies requires a relaxation of the model, allowing for single fixed points in the thread. A time traveller going back can easily create a paradox by making a modification that prevents his travel. Back to the Future employs a variant of this model, the Bendable Open Single Flow. Paradoxes can be created, but they need to be resolved. The thread of time constantly seeks to repair itself. Damage inflicted by time travellers will only slowly take effect as repair of the damage gradually gets more unlikely. Marty fades away gradually as his existence rapidly gets more unlikely. If he hadn't managed to correct the damage he would have disappeared. And here's the main problem of this model and time travel: if he never existed, how could be possibly go back in time to prevent his existence? In the OSF, this is not resolvable. In the BOSF, it's a little better. The character would appear out of nothing and disappear back into nothing, a fluke of time. But still, the OSF does not lend itself to time travel, even though it is the most intuitive model. Time Machine uses an OSF model too, but much more restrictive. I call it Fixed Open Single Flow (which is an oxymoron in its name). It is simply not possible to change the existing thread of time in a significant way. Alexander tries and fails. Unlike the BOSF, which tries to repair itself after damage is done, the FOSF doesn't allow any damage in the first place.
Forward time travel ought not to be possible in this model because the future doesn't exist yet. However, it would be possible to create a time capsule, in which the traveller is slowed down while outside the time passes. Time Machine, at least the most recent film version, looks like it does just that, but that's not true. A time machine of that kind wouldn't be able to travel backwards, neither would it be possible to change the future as the end of the film suggests. Which leads us to the next model.
Here we enter the realm of parallel, or rather intersecting, dimensions. The OMF model spawns a new reality for each and every possibility. Let's disregard the seeming impossibility of spawning an enormous (but finite) amount of realities each infinitely small time slice (unless there is a minimum division of time, a time quantum – but let's not go there).
This model is employed by Robert Jordan's Wheel of Time. Every possible world is a reality of its own. The less probable a reality is, the less clearly defined is the corresponding world.
Strictly seen, there is no free will in this model. You cannot choose, you always do everything. If you have a choice, you'll spawn as many worlds as you have possibilities, choosing a different one in each world. The less likely you were to choose a particular possibility, the less real the world is.
The core problem with this model is whether there is a main world and which it is. Is one world more important, more real than the others? Why is it this particular world? If it is the most likely one, how come that unlikely things happen to us? Wouldn't that mean that we don't live in the main world?
Terminator employs such a model. The T-80 was sent from a possible future, not from the future. It was sent from one of the possible worlds back to a point where it still was merged with many other worlds, its job being, if I recall correctly, to make that particular world the real one by killing Kyle. In Terminator 2, its job is reversed. It is sent to prevent the world it comes from from being the real one.
Of course, these changes are only interesting for the sake of the story, because the real world is the one that appears in the story. All the others are still spawned, and humans live and die in them. In this regard, there is no use in time travel in this model. Nevertheless, it's very possible and will never created paradoxes, as long as cross-travelling between parallel worlds is allowed. As such, this model is convenient. However, no one really believes that this is the model that is applied in Harry Potter. Many, however, believe that HP uses a mixture between the OSF and the OMF.
Quite frankly, I dislike this model. Essentially it is a large modification of the OSF, introducing some OMF traits. Again time is a single thread, but time travel can modify that. A time traveller is able to cut off a finished part of the thread and reweave it. In that case, there are multiple passes through time. There is a first time, in which everything is as if nobody every travelled through time. At one point in the future, somebody travels back. By doing this, he cuts of the existing thread at the point of his arrival and lays it aside, its only purpose being to provide existence to the time traveller and its existence only maintained by the memory of the traveller. The thread will begin to reweave itself, but this time there's the time traveller in it, equipped with knowledge of the future and capable of modifying it.
There is full free will in this model.
The nice thing about this model, even if most of its followers probably don't even realise it, is that it solves many of the paradoxes from the OSF without creating any new ones. The Grandfather Paradox, for example, is solved. I can go back in time to the point my grandfather lived. By doing so I cut off the entire part of the thread in which my father and I live and lay it aside. It provides existence there for me. I then go on to reweave a new thread. I kill my grandfather. In the new thread, neither my father nor I appear, but that doesn't matter. I'm there, come over from the cut piece of thread. Nobody in the real world has any memories of the events in the other piece of thread, of course, except me.
Getting closer to the model of Back to the Future, the separate piece of thread would eventually lose existence and fade, and me with it. But not necessarily.
The problem with this model is that it is not possible to go back and save yourself from dying or similar (a so-called Time Loop). And that's exactly why this model does not fit for Harry Potter. The first time around, Harry's soul is sucked out. Being an empty shell, he certainly is not capable of going back and saving himself. Suddenly the ending of Prisoner of Azkaban doesn't make sense any more. It is possible to save the logic, but only by jumping through hoops. Somebody who jumped through these hoops and wrote the possible sequence of events was Jack Ichijouji at the SugarQuill. He wrote the story To Change The Past, which shows Dumbledore travelling back in time to save Harry, to make it possible for Harry to travel back and save both Sirius and himself, too, which is necessary because by travelling back himself, Harry cuts off the thread in which Dumbledore travels back, which means that no one saves Harry if he doesn't do it himself, which would be his own undoing and thus making his travel pointless in the first place, unless Dumbledore goes back yet again, saving Harry again and sending him back again, so that Harry gets another chance at saving both Sirius and himself, and so on.
Another problem with this model is that even in the new weaving, the original instance of the traveller must find a way to use the time machine, else there are now two of them. But in the new instance, the events that prompted the traveller to use the machine never happened. One way is to kill the original instance. One episode of X-Files had something similar. Great. Another way would be to find another way of convincing him to use the machine, along the lines of, “You must go or this or that would have happened.” But does that mean he'll cut off the thread yet again? Or does the time machine work different this time around?
The thing is, this model is nice, but it is way too complicated to explain the events of Prisoner of Azkaban. The last model is far superior in this regard, though it may require you to leave behind some beliefs.
This model is completely different from the others. In the other models, if you're an observer outside of time, you see one or infinite threads weaving themselves as time passes. In CSF, you see a single completed thread and an ant, the Now, crawling along the thread, representing the passing time.
In such a model, everything is predetermined. Prophecies pose no problem at all, they're merely glimpses of different parts of the thread. Free will is an illusion. The characters don't know it, but every single one of their choices is already predetermined.
This model is unattractive to many because of this. They don't want free will to be an illusion. Personally I don't have any issues with that. If there is no way of differing between the illusion and reality, why is the illusion less real then? Why do the humans in The Matrix fight? They live perfectly normal lives.
Only, the illusion in Matrix is not perfect. Some people feel that it's an illusion, they resist it. As such, it should be fought.
But free will in a predetermined world? Since I don't know about what will happen, my choices seem to be free and seem to matter, and that's all I ask.
The nice thing about CSF is that time loops don't matter. It is already predetermined that in the future I will come back to save my current self, and thus there is no question of how I am capable of travelling to save me in the first place.
At the core, this is the model I believe applies to Harry Potter. But there is more, of which I will talk later. First I want to address a concern that ORF people often have with this model.
The objection is that Dumbledore helps Harry and Hermione in their travel. He delays the execution committee to give Harry and Hermione time. He knows they have to travel. In short, he knows too much.
But doesn't he always? There is a completely harmless explanation for Dumbledore's behaviour that doesn't require him to know about the time travelling at all.
There is a window in Hagrid's hut that shows the Pumpkin Patch. McNair watches Buckbeak through it before Fudge calls him back. When Harry gets Buckbeak, he is visible through this window. I strongly suspect that Dumbledore saw him or had some other way of knowing that Harry was there. Seeing the rescue attempt, he decides to assist it in his typical subtle manner, first by delaying McNair in going out and later by discouraging a search.
So far, so good. Later, Dumbledore speaks with Sirius and hears that at that very time, Sirius saw Harry somewhere else, without a Hippogriff. He guesses that Harry had indeed been in two places at the same time. This is only possible using the Time Turner he knows Hermione has. He goes to the hospital wing and tells Harry and Hermione to use it. Moments later, he lets the arriving children back into the hospital wing and closes the door. Finally he accompanies the fuming Snape back into the hospital wing and tells him – in a way that Fudge doesn't understand – that, yes, Harry and Hermione did free Sirius and they did so with his consent, so would Severus please shut up unless he wants to get Dumbledore arrested.
Yes, you heard me right. There is no way that Hermione could have had the Time Turner without at the very least the teachers who taught her at the same time, Hagrid, Trelawney, the Muggle Studies, Arithmancy and Ancient Runes teachers, knowing about it. Far more likely is that the entire staff knew about it. See my own fan fiction, Another Lesson. Snape is smart. He would have soon figured out that Hermione misused her Time Turner, proving him right about many things, including that he probably didn't like the idea of the Time Turner in the first place (that's my own guess, but a good one.) He would have turned Harry and Hermione (and, if somehow possible, Ron) in without much hesitation. Dumbledore knew that and had to prevent it. So he told Snape that it was his idea. Alright, let's go one where we stopped before.
It is repeated so often, yet seems so useless. If everything is predetermined, how can being seen matter?
There are multiple ways. I'll go for the simplest in this section and address the more complicated later.
First, there is the simple issue of the law. The list of people who know that Hermione used the Time Turner illegally is short. Harry and Hermione, of course, Dumbledore, Ron and Snape. Sirius most likely, Remus probably. McGonagall is a possibility. That makes eight. Had anyone else seen them, the entire story might have come out. It didn't as of 11:55 that particular night, but that was no guarantee for the future. You might say that if the future after that was predetermined, it didn't matter, but I disagree. Free will is free will, even if it is an illusion, but this is subject for an entire essay of its own.
The law about changing the past is one of the most important ones in the Wizarding World, so there are probably severe punishments attached to breaking it. This alone should be reason enough for them not to allow themselves to be seen.
But Hermione is also extremely worried about making bad things happen. In particular, she worries about themselves seeing them. If time cannot be changed, as in the pure CSF, and they don't remember seeing themselves, how would it be possible that they see themselves?
The world of Harry Potter is more complicated than that. In particular, the time machine in this world is based on magic, not science.
According to Einstein's Relativity Theory, if something accelerates to speeds higher than the speed of light (actually an impossibility, because its mass would become infinite), time would run backwards. This theory is the grounds on which many science fiction time machines are built, such as the one in the X-Files episode I mentioned.
But the Time Turner uses magic, not Tachyons. Magic, no matter the flavour, be it the near-scientific energy threads of Jordan's Wheel of Time, be it the living thing with unlimited power of Terry Brooks' Shannara or the peaceful emotional magic of Rowling's Harry Potter, is usually very complex. In most cases it is interleaved with the foundations of the universe. In our thread models, it surrounds and penetrates the weaving, often holding it together.
Rowling's magic is not a force of nature, but a force of the soul. Yet the source of the actual energy is nature, else permanently enchanting objects would not be possible. A magical performance draws the energy from nature, channels it through the soul, forms it in the mind and releases it through the body and often the wand. Emotions, willpower and memories play the most important parts in magic. Magical strength comes from the soul. Magical prowess comes from the mind.
The Patronus Charm is a perfect example. It requires a happy memory, happiness as an emotion, determination and confidence in the casting and a good deal of strength. Faced with the Dementors, Hermione lacked the confidence as well as a happy memory – there is not much chance she was fast enough to think up one. Harry lacks only the confidence. Faced with about a hundred Dementors, he doesn't think he's able to cast a Patronus. Later he has that confidence because he knows he'll succeed.
Magic is the source of the time travelling. Magic is the source of prophecies. Magic is also the force that sustains the events to come, the predetermined future. A disruption in the magic will disrupt the future. It will cause damage that may only be visible in the future, or that may lead to an immediate apocalypse. It may repair itself before the damage becomes visible, or it may not.
It has happened. According to Hermione, wizards have created such paradoxes. She knows no more, or tells no more. We don't know what the results were, but we can assume that they were unpleasant for everyone involved. If a wizards erases himself from the time line, magical backlash at the memories of him may kill the owners of these memories. Or the paradox of the idea of killing ones own past self may kill the one attempting to do so before he even gets the chance. I doubt that even J.K. Rowling herself has given it much thought. She isn't like this. She loves to play with us, placing clues and red herrings into the text, but she isn't very thorough when it comes to details such as these. They are of no importance to her or her story. We as the fans are left to struggle with them.
Another things about the law is that Time Turners comes from the Department of Mysteries. They research exotic things there: death, time, love and the universe. None of these can ever be fully understood. It is unlikely that the creators of the Time Turner themselves know the full consequences of their creation, which is one of the reasons why it is so hard to get one. You cannot test it either. How many volunteers to you find who go back in time to kill themselves? Less even than those who would voluntarily walk through the veil. That, at least, is a pleasant form of suicide.
Magic is also about intent. I do not think it would be possible to go back in time in order to save yourself. Doing so would create a paradox in your mind, subject to attacks by the magic. You cannot save yourself unless you're saved in order to do so. Unless things are predetermined and you know it. But that is not the case – you don't know what will happen. The bottom line is that I strongly believe that the magic prevents, or at least tries to prevent, time travel with the intention of changing the past.
But Harry and Hermione never intended to. When they used the time turner, Harry had no intentions at all; he had no clue what was going on. Hermione only had the intention of saving Sirius from something that had not yet happened. She only wanted more time to change the future, without having seen it pass.
Only when they had already travelled and where hiding in the broom cupboard did they decide to save Buckbeak. By then, that was a future event for them, not the past. Besides, neither of them had seen Buckbeak die. There was no paradox in their minds. Harry saving himself wasn't planned either. He just happened to be in the right place at the right time. As far as his past self was concerned, it was his father who saved him. While a paradox in reality, there is no paradox in Harry's mind.
What I'm saying is that in the world of Harry Potter, paradoxes in time travel are a thing of the minds of the observers and participants, not of reality. If I go back in time and kill myself, the problem is not that I'm not alive to go back, but that I'm dead even though I remember myself alive. Similarly, if I go back in time to change the past I've experienced, the problem is not in the reality that I must escape in order to go back, the problem is in the paradox in my own mind.
Harry Potter is different. We all know that. It was written by a woman. Only recently, in comparing it to other fantasy books, have I realised just how important this distinction is, how it shapes the character of the books. This world works in different ways than most. Time travel is no exception.
Always have Rowling's books sparked controversy. The time travel debate may be a small one compared to the larger debates like shipping, but I think it's more interesting in many ways. One thing is that we probably won't ever get more information from Rowling herself than what we have now. Unlike other topics, where eventually all debates will be ended by the truth coming out in the books, this is one of the topics where only consent can end the debate. It is up to us to make up this part of the world. It is a chance for us to extend this world we love so much, to make ourselves part of it.
Which I hope I have done.