This one's a romp; many Trek fans don't rate this as high as the well-known all-time classic episodes because it lacks the deep meaning or undertone of those really great ones, but this one is so well executed for what it is, so successful as pure entertainment, it always makes my personal list of the top half dozen episodes, no matter what mood I'm in. Several well known future movies ("Westworld") and TV shows (the more bland "Fantasy Island") took their cue from the premise of this episode (then, of course, the TNG show revamped the concept with the holodeck technology). Beautifully filmed (especially evident in the restored version and on DVD) and directed, it takes place in the nice park-like setting of a planet which the Enterprise has just arrived to. It's odd that no animal life, even insects, seems to exist here (how are flowers pollinated, for example), but things turn really odd when members of the landing party start seeing people from their past (Kirk has a people-heavy past, it turns out), as well as figures from other well-known fantasy stories. Sulu even finds an old-style police revolver (adding to his collection of swords, no doubt).<br /><br />By this point in the Trek series (halfway thru the first season), the main characters had pretty much solidified into the old friends we'd come to know over the many proceeding years. Here, we get to really see them relax, converse and work together to figure out this episode's puzzle: the strong narrative is a mystery again, of sorts, and the audience is along for the ride as Kirk & friends seek to unravel a very bizarre series of events which have a decidedly amusing flavor to them. It's almost whimsical, following up on the carefree style established up on the starship as Kirk was finally maneuvered into beaming down after showing definite signs of stress and fatigue (the Enterprise had, it's suggested, just completed a harrowing mission). Then Dr. McCoy is killed by a knight on horseback; yes, this is Dr. McCoy's final episode...just kidding. But, it's no joke to the rest of the landing party at this point in the story. McCoy really is dead for all intents and purposes and, like the best Trek episodes, the 2nd half of this adventure escalates to a more frantic, more desperate tempo of action and suspense. This is all signaled by Kirk's resolute response to Sulu, who voices his lack of understanding about any of these events just after McCoy's death - Kirk will get to the bottom of all this, come what may.<br /><br />But, it doesn't get much easier for Kirk: what follows is probably the longest staged mano-a-mano fight for the series as Kirk tussles with his nemesis from his academy days, a struggle that seems to take place over half the planet. Yet, this is counterbalanced by scenes of extraordinary tenderness, with another of Kirk's past acquaintances. This episode runs the gamut of all human experience, rather fitting in light of what we learn about the actual purpose of this weird planet. It's gratifying that the script really does explain all of what's happened, as opposed to some nonsensical approach which permeates many other fantasy & sci-fi series with similar plot lines (unexplained appearances by persons who could not possibly be there). And there actually is a subtext to the story - that we humans need to 'work' off our tensions and fatigue in a particular fashion, or we just don't function in a 'normal' natural way. Also, note the appearance of the very cute Yeoman Barrows and the sudden absence of Yeoman Rand, who did not return until the first Trek movie in '79. I believe that after this episode, even more Trek fans couldn't wait for the next appearance of all their favorite characters. But I leave this episode with a final, perhaps tantalizing thought: if McCoy was killed (verified by Spock), how do we know it was our real McCoy who beamed back up to the ship? Perhaps this explains why this McCoy was still inspecting starships about a century later and getting along very well with Data.