Rainbow Fish gets a bad report card (he gets a "C"). But when he accidentally spills ice cream (from a kelp gusher milkshake) on it at Wanda's, his parents mistake the "C" grade for an "A". Rainbow must prevent them from meeting Principal Gefilte and learning the truth. For getting a "C", changing his grades, and lying that he got an "A", he is cave grounded by his parents until he gets his grades up. This means until he gets his grades up, he is "cave grounded" except for school (meaning he can only leave the house to go to school while cave grounded).

Blue has a crush on Goldie, but he's too shy to ask her on a date, so Rainbow tells him what to say via a communicator made by Sea Filly. However, Chomper and Stingo soon ruin the plan.

When Ruby encounters a series of unfortunate events one day, she believes that she has been cursed.

Rainbow is embarrassed after failing to stand up to Rocko Rockfish (Alan Marriott), a bullying second grader.

Phineas T. Gronch is planning to permanently demolish the Mollusk Reef Villas as well as wipe out half of Neptune Bay to build a shopping mall in its place. Rainbow, Blue and Sea Filly have to stop him in time, or they'll all be for it.