Recently, someone suggested to me that the 1984 movie The Terminator might be a GU story, and sure enough, upon re-watching it (under some amount of protest, as this is not really my sort of movie), I found that it was.
As with many GU stories where the protagonist is an adult woman, the object is saving her child – only in this case, it is a child that is not yet born. Sarah is being stalked by a cyborg from the future who wants her dead to prevent her future son from leading a revolution against the machines. Her companion is a man sent from the same future to protect her. While he doesn’t betray her, she does temporarily think he has made it all up. She also briefly returns to the “real world” in the middle of being on the run. In the end, her companion is killed, and Sarah must defeat the Terminator alone.
(Side note: the future date is 2029, now closer to our present time than we are from the year the movie was made!)