An inexperienced U-boat crew are plunged into a perilous secret mission, while new translator Simone starts work at the base. Gripping World War II drama.

Hoffmann insists on further training despite the crew's desire to head to battle. Meanwhile, Simone pieces together the previous night's events in La Rochelle.

Tennstedt and Hoffmann are forced to put their differences aside when an enemy ship comes into view. Meanwhile, Carla plans a mission in La Rochelle.

Hoffman and Tennstedt's continued conflict puts their mission in jeopardy. The crew's unity continues to crumble in the wake of an enemy strike against U-612.

A new arrival quickly takes Greenwood's place aboard the U-boat. Meanwhile, the crew continues to squabble over their loyalties.

Things look bleak for the crew of U-612, as they desperately try to work out their next move. Simone adjusts to her new position between Carla and Forster.