lifted the "spine" of the plot from the 1972 Doctor Who serial "Day of the Daleks". Sequels Though Byrne had intended "Days of Future Past" to be a completely self-contained story, with the future world seen in the story no longer existing even as an alternate timeline following the conclusion, a number of stories have revisited this future and even acted as outright sequels. Rachel Summers, a character seen in the future segments of "Days of Future Past", later travels through time to the present day and joins the X-Men. A supervillain, Ahab, follows her to the present in the "Days of Future Present" crossover. In this story, Ahab kidnaps the children Franklin Richards (son of Mister Fantastic and the Invisible Woman and, in the future timeline, Rachel's lover) and Nathan Summers (son of Cyclops and Madelyne Pryor) but is defeated by the X-Men, X-Factor, the New Mutants and the Fantastic Four. Rachel joins the European mutant team Excalibur, whose series twice revisited the "Days of Future Past" timeline. The first time was in a story by Alan Davis entitled "Days of Future Yet To Come", in which a time-traveling Excalibur and several Marvel UK heroes overthrow the Sentinel rulers of future America. This storyline also reveals that Excalibur's robotic "mascot" Widget had been possessed by the spirit of the future Kitty Pryde. A similar but distinct reality is seen in a vision by her teammate Captain Britain. This story, "Days of Future Tense", reveals the final fate of that timeline's Excalibur team. A prelude to "Days of Future Past" was produced in a three-part mini-series entitled "Wolverine: Days of Future Past". This three-issue mini dealt with ramifications between the catalyst for the creation of the alternative future up until the main storyline in Uncanny X-Men 141–142. The prelude explains why Logan leaves for Canada and why Magneto is in a wheelchair in the main two issue story. Another view of this reality was presented in the second issue of Hulk: Broken Worlds. A short story, "Out of Time", examines the life of Bruce Banner (the Hulk) in a Sentinel prison camp. Secret Wars (2015) A sequel based on the original storyline written by Marguerite Bennett, Years of Future Past, was released in June 2015, featuring the "Days of Future Past" timeline depicted in the 2015 "Secret Wars" storyline. The setting on Battleworld is called the Sentinel Territories. Major characters