As Akeno becomes worried about Moeka's distress call, the Harekaze intercepts a message reporting the ship's alleged mutiny. Later that night, the ship comes across the I-201, a submarine from Toumai marine boys' high school and attempts to send a message to them, only to once again come under attack. As the girls try to evade the submarine's torpedoes, the rescued German pilot, Wilhelmina Braunschweig Ingelner Friedeburg, wakes up and helps the crew fight off the submarine. After managing to escape, Wilhelmina informs Akeno that something on the Spee caused her crew to stop obeying orders. As the ship receives orders from Yokosuka's principal to return to school, Wilhelmina moves into Mashiro's room.