A scientific experiment begins, and as the button is pressed, the unexpected occurs: everyone in the world goes to sleep for a few moments while everyone's consciousness is catapulted more than twenty years into the future. At the end of those moments, when the world reawakens, all human life is transformed by foreknowledge.

Was that shocking revelation a peek at the real, unalterable future, or was it only one of many possible futures? What happens when a man tries to change it, like the doctor who has twenty years to try to prevent his own murder? How will the foreknowledge of a part of “then” affect the experience of the “now”?