This is a series. Set in the Marvel Cinematic Universe universe.
An amnesiac soldier fighting for an alien empire crashes into a Los Angeles video shop in 1995 and slowly works out that she is human, that her memories were taken, and that the refugees she has been hunting are the victims rather than the enemy. Set before every other film in the run, and it quietly changes who the audience thought S.H.I.E.L.D. had been fighting for.