The future past is a place that conscernce the setinels.so they were made by a scientist named trask so we're going to tell you the story from the movie x-men days of future past. So the setinels have taken control in palace called dark New York where there are only a couple mutants left . So shadow cat figures out she has another power where she can send things back in time so wolverine with his healing factor has shadow cat send him back.the reason he has to is to get magneto and Charles to work together to convince trask that mutants aren't all that bad.but you know magneto he tricked everyone and eventually wolverine gets working together to save the future.but let's go back so trask is telling everybody about the setinels but everyone is like I don't know about these setinels. So eventually he finds out about mystique that she can turn into anyone. So he is. Like we need that DNA so the setinels can blend in and kill mutants at the time.so wolverine eventually saved mystique and saved all mutants and people.