Smoke and Mirrors

A group of mercenaries ambush a prison van and abduct the prisoner, transporting him to a safe-house high in the Sierras. But when the prisoner escapes, the tables are turned and the hunters become hunted. Initially, it appears the prisoner is enacting revenge - That is until his frozen corpse is discovered in icy woodland. So, if he is not performing the executions, who is? And why?