Vanessa Kellerman sees her parents drown when a Nazi U-Boat torpedoes the British ocean liner, Athenia. She returns to Mobile and steels herself to step into her fathers position, learning to run a shipping company in partnership with her uncle. Two years later, in her hometown on the Gulf Coast, Vanessa faces the terror once again.
It is in December of 1941, soon after the bombing of Pearl Harbor, that the FBI sends agent Jack Conway to Mobile to ferret out espionage activity. Alabamas port city is vulnerable, teeming with critical defense industries and one of those is Kellerman Steamship Company.
At the glittering Strikers Ball on New Years Eve, Jack meets the beautiful Vanessa, while a German sub slides into Mobile Bay. Two Nazi saboteurs make shore, bury their explosives and merge into the unsuspecting community.
In the next few days, it becomes apparent to Jack, Vanessa, and old salt, Scotty McKee, that there is a sinister force operating in their midst. With time running out and a significant portion of Americas defense at stake, they must peel away the layers of camouflage to expose the danger and stop this silent invasion.