A killer whale - Orkie - returns to Quetzo to settle an old feud with Flipper. Dexter, determined to provoke a big showdown between the two, gets Orkie really angry and then convinces the rest of the town not to help Flipper. Finally Flipper and Orkie and they end their feud to save the school.

Dexter and his henchmen have a big feast, but make a mess of Quetzo with their litter. Flipper makes them clean it up, but the sharks secretly dump it in the Big Deep. The next day Iloka is terrorized by a huge sea serpent. Lopaka and Flipper discover that the serpent is from the Big Deep, and has some of Dexter's rubbish caught in its throat.