When you watch X-Men: Days of Future Past online, you’d be taken to a different kind of world. After believing that mutants can threaten humanity in the future, Dr. Trask comes up with robotic weapons called the Sentinels. They are capable of detecting mutant genes and in the turn of the 21st century they have turned out fast to become effective killing machines. As mutants became highly extinct, Wolverine poses up as a volunteer to go back in the past and gather up other members of the X-Men in the past to save their very own race’s future.
Charles Xavier tells Wolverine that it was Mystique who is responsible for all rising chaos. They learned that she looked for Dr. Trask only to kill him. Mystique would then be caught and her ability to shape shift or merely change was further studied and even added to the adaptability of the Sentinels. Wolverine needed to go to the younger version of Charles in the past for help. However, the problem is that that Charles was of low spirits at that point in time due to his condition. He was without any of his powers since he took in a drug that will make him walk but stop his powers from working in effect.
Xavier explains via a voice over how events can cause waves of time. And the more waves are made, the flow of time can be altered as well. Wolverine’s body was seen recovered by the military with William Stryker taking him in. But it was unveiled that it was just Mystique who disguised herself as Stryker. In post credits, people are seen worshipping a bluish mutant named En Sabah Nur. Finally, four people riding horses all in black were shown who apparently are Apocalypse and the Four Horsemen.