Barnacles, Kwazii, Peso, and Shellington are on a beach, when they discover a sea star inside a seashell. She introduces herself as Twinkle, and Shellington points out she doesn't look like the other sea stars at the beach. Twinkle explains she doesn't live at the beach and she got lost, so the Octonauts take her to the Octopod to help her out. At the Octopod, she explains that a large underwater wave dropped her onto that beach. Barnacles instructs Kwazii to sound the Octo-Alert, and calls the Octonauts to the Launch Bay.
Barnacles declares that the mission for today is to search the ocean for Twinkle's home. Kwazii and Peso join him in the Gup-A, and they start by exploring a reef in the sunlight zone. They meet a sunflower sea star, but while talking to him, they come across a pufferfish. Peso hides Twinkle underneath a hat he made out of bandages, and the pufferfish swims away. Moving on to the twilight zone, and they meet some brittle stars. They tell her that she's likely not from the twilight zone, and while they swim back to the Gup-A, a wolf eel chases after Twinkle. Kwazii, Peso, and Twinkle quickly hide inside a cave, and Barnacles scares away the wolf eel. Inside the cave, they discover Twinkle can glow. Barnacles figures out that creatures who glow live in the midnight zone, and they move further down.
While driving to the midnight zone, Twinkle slips and accidentally causes the Gup-A to land onto the bottom of a very deep hole in the midnight zone, causing it to crash and get stuck. They free it, but the Octonauts realize they don't know the way out due to the lack of light. Suddenly, lots of little lights shine around them like stars, which turns out to be Twinkle's family! The sea stars help guide the Octonauts back home using their light, and say goodbye.
Tropes
- Loud Gulp: Peso does one when Kwazii tells him the possibility of having to explore dangerous places to find Twinkle's home.
- Screw This, I'm Out of Here!: The wolf eel swimming away from Barnacles after being scared off.