The Fighting Marines
The United States Marine Corps is building a landing strip on Halfway Island, in the Pacific Ocean.
The construction work disrupts the hideout of 'The Tiger Shark', a masked criminal. In revenge 'The Tiger Shark' sabotages the marine's work and kidnaps one of their number, Sergeant Schiller.
Corporal Larry Grant and Sergeant 'Mac' McGowan, who are rivals for the attentions of Sergeant Schiller's sister, set out to rescue him and defeat 'The Tiger Shark'.