An ambitious young lawyer discovers a way to travel through time to fix his relationships and create his perfect life, but even when he knows what's going to happen next, he can't control everything.

After Montreal police officer Mia Coleman and her partner Tyler take a lenient approach to a marital dispute, the husband, Paul Whitman, murders his wife Keri and their two small children, then kills himself. But Mia has stumbled across Plan B and finds herself able to book a trip into the past, and perhaps alter the outcome.