Princess Merlinda, Sasha, and Nerissa emerge from the sea, embarking on an adventure to stop Pirate Barbarossa's nefarious plan of draining the ocean's magic

New girl Trinity moves in across the street from creepy neighbor, Mr. Peterson and quickly befriends Nicky, who is already obsessed with finding out what horrific secrets are hiding in Peterson's basement. They enlist their less courageous friends to join them in their terrifying stealth missions to help rescue whatever is trapped in that horror house basement.