The Enemy Below (1)

A nuclear submarine is attacked in the Atlantic, forcing the League to come face-to-face with Aquaman and his Atlantean army. Aquaman takes Superman up on his advice to go to Metropolis and take his problems up with the various governments of the world. When a mercenary Deadshot attacks Aquaman, the League steps in. Aquaman discovers that Lord Orm, his own brother, was behind the attack. Orm takes Aquaman and his infant son and places them on a cliff over a vein of molten lava, leaving them to die. In order to save his son, Aquaman must make the terrible sacrifice of severing his own hand.