At the Kriegsmarine headquarters, Kessler talks to engineer Holzer, who is responsible for the secret plan to build a research facility on the bay. They talk about using Polish specialists who know this reservoir well during the construction of the center. Franz comes to the command. During a conversation with Ilse, he manages to obtain a secret document regarding the resort being built on the bay. He is summoned by Kessler. He learns from him that his brother, Otto, died at sea during combat.

Franz visits his father and tells him that he works for the Allies. He asks him to help him sabotage the torpedo tests. In order to include Kurkowski in the secret homing torpedo program, he convinces Engel that the Polish engineer is a valued expert on this part of the bay. At the same time, Franz learns that the SS is looking for Lotta in connection with Kurt's death. He immediately warns her and asks her to escape from Gdynia.