What if you could go back in time to save a life? What if you could avert disaster? Karen Warren finds herself in the middle of an emergency, with the power to turn back the clock and rescue a battered womn. Her car breaks down on a hot Texas afternoon, and Frank, a despicable and lecherous man, gives her a ride. On the way, he begins to fight with his wife. The wife is accidentally killed, and Karen runs in terror from the car and into the United States supercollider laboratory looking for help. Instead, she stumbles onto a scientific experiment and is sent back in time..