Five episodes from the animated adventures of Sub-Mariner. Episode 1 sees the Sub-Mariner return to Atlantis to save his city from the evil warlord, Krang. In episode 2, Prince Namor embarks on a quest for an enchanted trident, while Lady Dorma rejects the advances of Krang. In episode 3, Atlantis is rocked by an earthquake. The Prince goes to the surface to stop human scientists from destroying Atlantis with underwater drilling. Episode 4 sees Atuma the Barbarian attack Atlantis and send a robot to kill the Sub-Mariner. Namor must destroy the alien robot to save his city. And in episode 5, Lord Bashy is accused of stealing the enchanted trident, but Atuma took it and imprisons Bashy in the forbidden cavern. Sub-Mariner must save Lord Bashy from entombment.