30 second spiel

There is a guy who is a brilliant scientist. He has been working on space-time dimensions all his life and has hardly made any social contact. However, guy finds woman who shares the same visions. Guy falls in love with woman. Guy is about to marry woman. Woman gets in terrible car accident and dies. Guy is awestruck with grief and trashes his lab. . . until he figures out the the answer to time-traveling. He goes back in time in order to prevent her from driving that day, but instead of a car crash, the woman gets murdered by a drive-by shooting. Moral of the story? Fate can't be changed.