An inexperienced U-boat crew has to survive a secret mission and a young German woman is torn between loyalty for her home country and the French resistance in the WWII drama.
Unity on U-612 has crumbled and Hoffman and Tennstedt's continued conflict could jeopardise the mission. On land, Simone wrestles with a difficult choice.
A surprise new arrival takes Greenwood's place, causing a divide. Plus, Carla and Simone grow closer and a resistance fighter arrives at the safe house.
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.