Hubert is losing his best friend to a bully. Meet Rainbow Reef's fabulous fish kids: Emma and Aiden, the panicky pufferfish twins, Sparky the doggone friendly dogfish, Olga the eight-legged bully, Sturgeon the (wannabe) Surgeon, and Hermit, a tiny hermit crab with sky-high ambitions. Hubert wants to play cards with his best friend Sparky the dogfish. Too bad Sparky's other friend, Olga Octopus, thinks Hubert is too small to play. When Hubert accuses Olga of cheating, she carries him out past the drop-off and abandons him where the sea monsters live.