It's 1943, World War II is well under way, and Ensign Peter Maxwell is enjoying easy days in San Diego as base choir director and warm nights with his new bride, Kay. But there's a war out there waiting to be fought, and Pete wants to be part of it.

When a request comes up for officers on an ammo ship (prophetically named after Pete's Iowa hometown, Liberty Hill), newly promoted Lieutenant Maxwell and the rest of his vocal quartet, the Fantail Four, volunteer. The duty they pull is dangerous even for wartime: the young officers find themselves in charge of a ship of largely untrained African American sailors who hail from big-city ghettoes, Dixie farms, and all ports in between.

As the racially tense Liberty Hill Victory pulls into San Francisco's Port Chicago, the crew witnesses a horrific explosion that paints the sky red. In the wake of a mutiny by the port's surviving black sailors, protesting unsafe conditions, the Liberty Hill must step in to load ammo. This difficult task is made nearly impossible for the Fantail Four by a racist captain who would love to see the "colored" crew and his "college boy" officers fail. But when Lieutenant Maxwell finds an ally in seaman "Sarge" Washington, a former cop from the Black Belt of Chicago, the deadly job gets done, if not without incident. . . .

They then sail into two violent storms - a literal typhoon that could put them on the ocean's floor if their cargo doesn't blow them to hell and gone first, and a figurative one when a white officer is found brutally murdered in Shaft Alley, the very bottom of the ship where the drive shaft turns the propeller. And in the midst of a vast ocean and a wider war, a farm boy from Iowa and a tough cop from the ghetto must combine forces to stop a vengeful murderer who threatens to ignite their floating powder keg.