Tennstedt and Hoffmann continue to butt heads aboard U-612, while rebel Carla Monroe plans a mission in La Rochelle.

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.

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

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