Picking off from last episode, the girls examine the damage done to the Grand Ocean Kingdom, during which, they stumble across a room housing seashells containing memories of mermaid who encountered humans before Laura while Butler seals the Marine Ring. The girls meet the real Mermaid Queen, Melusine Muses Mnemosyne, who explains the Witch intends to use her Fool's Casket to gain immortality and make everyone lazy. She also notes that Laura had recovered her memory of her first meeting with Manatsu when she was younger, clarifying that mermaids who meet humans must have their memories of that encounter to be erased via a machine...