In what's known as the multiverse, parallel universes exist where multiple versions of the same person live in each of them, unaware of the others' existence. That is, except for Gabriel Yulaw (JET LI) and a group of agents who are after him. It seems that Yulaw, a former agent himself, is traveling to all of the alternate universes, killing the other versions of himself and thus absorbing their power. With the body count up to 123, Yulaw needs to kill just one last version before acquiring ultimate power.
Since both murder and travel to alternate universes are illegal, Yulaw is a wanted man and his capture now lies in the hands of agents Harry Roedecker (DELROY LINDO) and Evan Funsch (JASON STATHAM) who know they can't kill him lest his one remaining alternate self, Gabe Yulaw (JET LI), attain that power.
Accordingly, Roedecker and Funsch arrive in our world where Gabe is an L.A. cop living with his veterinarian wife, T.K. (CARLA GUGINO). From that point on and as the two men try to stop Yulaw, Gabe does what he must to protect himself from his doppelganger's various attempts on his life.