Famous photographer Larry Martin receives a visit from his brother Philip, on leave from military service in West Germany. Philip is trying to find the wife of a deceased friend and his search takes him to Dublin. Sometime later, Larry learns that Philip never went to Dublin, but instead has disappeared.
Philip briefly returns to his brother Larry from the Army, with a story about needing to head to Ireland, but instead stays in a hotel, where tragedy awaits.
Larry is convinced his brother's death wasn't suicide, and, with another close death, takes matters into his own hands.
Larry is questioned by Hyde as his prints are found on the knife. Larry and Ruth visit a nightclub and find a familiar looking couple.
Larry talks with the couple in the strange photo, and discovers his brother was in possession of a vast sum of cash.
Larry must think on his feet to deal with an armed assailant, and also has to make a decision about a parcel intended for his brother.
Larry is placed in real danger, as efforts to get hold of the key he'd copied are stepped up.