The Devil's Sea Mystery is the fifth episode of Season 1, and the fifth episode overall.
Synopsis[]
"Are aliens stealing things from an island and dragging them underwater? Ant believes that's perfectly reasonable. The Nektons investigate and find something even more dangerous! But can they escape?"
Plot[]
On the remote island of Hachijo-Kojima, a blue light climbs onto shore and approaches a house. A man sleeping inside wakes up and sees the light take his fridge.
On the Aronnax, Ant is in his room studying books on aliens and is also getting ready to move Jeffrey into a larger fish bowl when Fontaine arrives and brings him to the bridge where Will and Kaiko want to show them both something. They bring reports of a recent anomaly in the part of the sea known as the Devils Sea, a round shape that appears to move and sometimes disappear, Ant believes it to be aliens, they also review footage from a mini-sub that investigated the object before it disappeared. The anomaly's location is near Hachijo-Kojima whose only resident is a man named Kenji (who Ant recognizes) who believes that aliens stole his fridge.
The Nektons agree to meet Kenji but upon arrival they get caught in one of the traps Kenji set up for the "aliens". While talking to Kenji the blue light returns and this time takes Kenji's water tank, the Nektons pursue it back to ocean. Determined to figure out what it is Will takes the White Knight to investigate and encounters the anomaly from the mini-sub footage, Will slowly approaches it then suddenly gets sucked into it and the object starts moving away.
The object moves into a tunnel, unable to follow in the Aronnax Kaiko, Ant and Fontaine take the Rover to search for Will, as they search they find the missing mini-sub which appears to be hollowed out and stripped of its technology, they also find Kenji's water tank and fridge and various other objects. Ant notices how all the objects are lined up smallest to biggest identifying it as a vacancy-chain. Suddenly Will appears and the blue lights are revealed to be giant hermit crabs, one of which tears apart the Rover to make as his new home. The three are able to escape but are attacked by other crabs, using the White Knight their able to get back to the Aronnax.
The Nektons tell Kenji about the crabs and the cave and that the carbs kept taking things from him because they needed a new home as they grew, to prevent this the Nektons bring several hollowed items to the crabs so they stop taking Kenji's stuff. To thank the Nektons Kenji allows each of them to take an item from his collection, Ant takes a decoration for Jeffrey's bigger fish bowl while Will takes a strange coin.
Upon return Jeffrey is shown (through trials and errors seen throughout the episode) to be already in his bigger fish bowl, Will identifies the coin as being Lemurian implying that Lemuria wants to be found.