Jason, Zack, & Trini go scubadiving. Billy's invited, but declines, as this brings up bad memories from his childhood. As a boy, he had a finger-biting experience with a fish! Since then, he's been afraid of aquatic animals. Rita exploits this fear, sending down the Toxic Goo-Fish monster. Can the Blue Ranger manage to overcome his fish phobia, and filet the fiend?