The Octopod Mystery
Season 04, Episode 03
The Octopod Mystery
Episode guide
The Hidden Lake
The Baby Sea Turtles


The Octopod Mystery is Season 4 Episode 3 of the Octonauts series. After the Octopod has broken down, Tweak manages to seek out a new part from an old, abandoned Octopod which has been transformed into a artificial reef. But they are not alone...


Sea creatures

  • Giant Pacific octopus

Sea creature debuts

  • Giant Pacific octopus

Creature Reports

Giant Pacific Octopus

Plot summary

The broken bubble converter

When Dashi activates the Octopod's launch sequence, it struggles to leave the ground and stops moving. Captain Barnacles asks Tweak what happened, and she realises that a vital part of the Octopod's engine, the bubble converter, has broken. Kwazii suggests making a new one, but Tweak says that that could take a while. Suddenly the Octonauts notice that the Octopod is about to fall off the edge of a cliff, in danger of falling onto sharp rocks below. Barnacles says that they don't have time to make a new bubble converter, but they have to do something immediately. Tweak then mentions that there is another working bubble converter, which makes Barnacles and Professor Inkling remember something from the past: the old Octopod. Kwazii and Peso are taken aback by this, so Tweak tells them that the current Octopod is actually an upgrade of an old version. it later becomes apart of the Octopod,s engine

Tweak explains to a confused Kwazii and Peso that before the Octonauts were founded, they used to travel in an old Octopod. This ship never worked properly and eventually they crashed it. Professor Inkling adds that when they went back to fix it, it had become an artificial reef, so they had to leave it. Tweak says that this Octopod should still have its bubble converter, so she leaves with Barnacles, Kwazii and Peso to retrieve it. Dashi, Shellington, Inkling and the Vegimals are left in an unsteady Octopod which threatens to fall off at any moment, so they run across the room to keep it level.

The old Octopod

The old Octopod lacks a working Octo-Hatch, so the Octonauts enter through its steering wheel. They arrive in an abandoned HQ, but Tweak notices the chairs have been stacked strangely, not at all how she left them. As they don't have much time, she dismisses it and finds the bubble converter. But suddenly, the lights go off and Tweak notices that the bubble converter is gone! Barnacles says that they have to find whoever stole it and tells Tweak to sound the Octo Alert. She tells him that this Octopod's button wouldn't still be working, so he sheepishly sounds the Octo Alert using his Octo-Compass.

The Octopod Mystery

The montage shows the other Octonauts falling over and bumping into things, due to the Octopod's movements. Because of this, they do not hear what Captain Barnacles is saying about the situation. So he tells Tweak, Kwazii and Peso to split up and find the thief as quickly as possible.

Peso enters the Octopod's sickbay, but an orange creature with tentacles shuts him in the room. Kwazii goes to the game pod, and tackles what he thinks is the creature, but is actually just a volleyball. He is then attacked by eight balls at once, puzzling him. Tweak enters the launch bay and notices again that things are not as she left them. But when she moves some barrels, she is temporarily blinded by ink and the barrels are exactly as they were before, with no explanation. Captain Barnacles visits the library, which has no books on the shelves, but one is on the floor. As he reaches to pick it up, a tentacles grabs him and throws him to the ground. Just then, Peso, Tweak and Kwazii enter the library and look slightly confused as to what the captain is doing on the floor.

Captain Barnacles decides to contact Shellington, so they can work out what this creature actually is. After the Octonauts tell him it has tentacles, can throw eight things at once and squirt ink, and is orange, coupled with the fact that it is living in an old ship, he realises it must be a Giant Pacific Octopus, much to Tweak's amusement. She reveals that when originally designing the Octopod, she built it to look like this very creature. When Kwazii asks why it would steal their converter, Shellington tells him that giant Pacific octopuses are very curious and clever, so it probably wanted to investigate it. This gives Barnacles an idea.

The thief revealed

The Octonauts lay a trap for the octopus involving a flashing torch and a box. Just as they'd planned, the giant Pacific octopus reveals itself and gets into the box. Tweak pulls a rope and the octopus appears to be caught. When Kwazii opens the box, the octopus is apparently gone, but it was actually just hiding on the roof of the box. She says hello to them but quickly swims away, still holding the torch. The Octonauts give chase, so the octopus throws metal barrels at them to slow them down. Then she hides by sticking to a wall, but her torch gives her away. While escaping to the HQ, she bumps into a ladder and drops the torch. Tweak and Kwazii quickly seal off all exits to the HQ so they can find and catch the octopus. After a quick search, Barnacles spots her hiding inside the steering wheel pod. The octopus angrily calls the Octonauts "invaders" and reprimands them for moving everything around in her home. Barnacles apologises and tells her they only want their bubble converter. She tells him that it belongs to her as it was in her home. Barnacles then feigns ignorance to the fact that it is not hers, and asks her if she wants to trade it for his torch. She thinks about it, then happily accepts.

All's well that ends well

With the new bubble converter installed into the current Octopod, Captain Barnacles drives away, satisfied. When he comments on how the Octopod is running perfectly, the scene cuts to an exhausted Shellington and Dashi, who responds by saying she's just glad they aren't running anymore. The Octonauts then pass by the old Octopod, and wave to their new friend who is joyfully playing with her torch.


  • Kwazii and Peso acting confused about there being an old Octopod may suggest that they joined the Octonauts some time after all the others.


  • Peso refers to a torch as a flashlight, which is not correct British English.