S4·E28 Four Days to Kill

Synopsis

Johnny, a professional assassin with a hair-trigger temper, is sent by his boss to Havana to do a job. His target is his former mentor, Barney Moyer, the man who taught him everything he knows about killing. That's why the intended victim knows Johnny will spend three days watching him and move in for the kill on the fourth; Barney anticipates Johnny's every move.