An untested captain. An experimental submarine. And a mission that could change the course of World War II.

December 7, 1941. America reels from the attack on Pearl Harbor. Battleships burn... Thousands dead... The United States Navy prepares for vengeance in the Pacific.

But while the nation turns its eyes west…Germany strikes from the east.

Hitler and Admiral Dönitz unleash their U-boats along America's Atlantic and Gulf coasts, targeting Allied shipping with ruthless precision. Merchant vessels vanish. Crews are lost. Panic spreads.

The attacks feel coordinated. Calculated. Almost guided.

Then intelligence reveals a chilling possibility — a Nazi spy ship may be directing the onslaught from the shadows.

To find her, the Navy deploys an untested weapon: the experimental submarine USS Bull Shark.

Her mission is simple.

Locate the spy ship.

Sink her.

Stop the attacks.

Commanded by young Captain Art Turner and crewed by men with everything to prove, the Bull Shark begins her shakedown cruise — now transformed into a deadly hunt across hostile waters.

Outnumbered.

Operating alone.

Facing seasoned German submariners.

If they fail, America's eastern seaboard and Gulf coast could become the next battleground.

The brand new war has come home.

And the Bull Shark is the only thing standing in the way.