Morgenrot

In 1915, Captain Liers, commander of a submarine is leaving his hometown, where he, his 2nd officer and the radio-operator, who is married there, spend their shore leave. Liers two brothers were already killed in action, so his mother doesn't like the idea of him going back to his sub. Liers thinks his 2nd officer is in love with a local girl, who is really pining for him. On patrol they sink a British armoured cruiser, but while returning to their harbor, they're attacked by a sub trap.