Lester Gruber has been given the job of laundering Captain Binghamton's uniforms. When a Japanese sub fires on the PT 73, the uniforms are destroyed, and Lester's finger is scratched, prompting him to put in for a Purple Heart.

Binghamton grants McHale and the 73 Crew a week's liberty in New Caledonia, but they must postpone their trip, when the 73 turns up missing, and they have to scheme to get a replacement.

When McHale and his men are assigned the duty of averting a Japanese attack on a US convoy, they use the soundtracks of movies starring John Wayne, Humphrey Bogart, and Errol Flynn to confuse the enemies.