Code Name: Diamond Head

Johnny Paul (Thinnes) is a flashy gambler and ladies' man living on Oahu. In reality, he is an agent working for secret US government agency. He is assigned to a mission to stop the theft of a deadly new gas, which has the potential to cause instant death upon contact. The substance was being secretly created by a top battalion of Marines at the request of a The Pentagon official. However, a double agent had infiltrated the unit, killed the executive, and assumed his identity. Paul uses his image to get close to the double agent, who is known by the pseudonym "Tree". However, once his cover is blown, it's a race against time to stop Tree from selling the secrets to an unnamed foreign power.