Jonathan Ecks, an FBI agent, realizes that he must join with his lifelong enemy, Agent Sever, a rogue DIA agent with whom he is in mortal combat, in order to defeat a common enemy. That enemy has developed a "micro-device" that can be injected into victims in order to kill them at will.

A woman who has recently discovered that she is the daughter of Angelo, a major mafia boss, decides to wreak vengeance when he is killed by a hitman. She's aided by his faithful bodyguard, with whom she soon falls in love.

When a hunter sent back to the prehistoric era runs off the path he must not leave, he causes a chain reaction that alters history in disastrous ways.