When a United States Senator is brutally murdered, the evidence points to a Soviet assassin codenamed 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.