When a United States Senator is brutally murdered, the evidence points to a Soviet assassin code-named Cassius, who was long-thought to be dead. Two men who know Cassius best are thrown together to catch him. Paul Shepherdson is a retired CIA operative who spent his career tracking Cassius around the globe. Ben Geary is a hotshot young FBI Agent and family man who has studied the killer's every move. Ben thinks he knows Cassius, but Paul knows he is dead wrong. Now, time is running out to stop this merciless killing machine before he finds his next target.