The Sunken Gallery is the seventeenth episode of the first season of the animated series.
"The Nektons are arrested for stealing! Ant and Fontaine escape to prove their innocence, but whoever set them up is already two steps ahead. Clearing the Nekton name won't be easy - especially with a spy aboard the Aronnax!"
Ant and Fontaine are out in the Rover collecting old items that belong to a sunken ship cold the Minerva, Fontaine tries to explain to Ant that the Minerva holds priceless artwork that hasn't been seen for decades the most coveted being the painting called "Child with Kraken" a painting that was never photographed but Ant cares little for art. Suddenly multiple submarines appear and surround the Aronaxx Will and Kaiko then receive a message from Commander Pyrosome telling them their under arrest!
Pyrosome and her men board the Aronaxx along with her second in-command captian Hernandez, she tells the Nektons that the Minerva has disappeared they believe at least one of them was involved in stealing it. Kaiko explains that a salvage company has hired them to search the ship but when Hernandez checks the tracking logs it shows the Aronaxx had visited the site yesterday the time of the theft they but Kaiko says it's not true, they also find a video of what appears to be Ant swimming out of the Minerva with an item but Ant says it's fake. Pryosome's men search the ship all over until Pyrosome makes Will open his safe in the study Hernandez showing particular interest in the piece of the Ephemychron Will has but also finds a painting that appears to be "Child with Kraken". This all but confirms Pryosome's suspicion and she has Ant and Fontaine put in custody and keeps Will and Kaiko in the study for questioning.
Ant is put in his room and Fontaine is put in the kitchen since her room is too close to Ant's, while in his room Ant has Jeffery swim between rooms to deliver messages to and from Fontaine and tells her he's going to get them out, using his tablet Ant activates a message from the Swamp Knight in the moonpool which distracts the guards allowing him escape and free Fontaine. Using the Shadow Knight's stealth mode Ant pushes Fontaine in the Rover to avoid being detected on sonar but barely escape along after a brief chase, they then head to find the Minerva and clear their names. Back on the Aronaxx Pyrosome becomes aware of the children's absence and starts to question Will and Kaiko while Hernandez returns to the bridge, Will is particularly upset over the whole thing making him lash out.
Ant and Fontaine reach the Minerva's original site and find drag marks but realize their a decoy since it would easier to lift something that large. On the Aronaxx Will believes the W.O.A. is setting them up to get something and notes how interested Hernandez was in their piece of the Ephemychron. Ant and Fontaine find a lift bag on the sea floor and after scanning areas where a ship could be hidden they find the Minerva, Ant checks inside to make sure the art is still there and finds there is breathable air inside but hides when he hears voices which turns out be there old foe Sebastian Conger pilfering the Minerva of it's artwork to sell. After hearing this Fontaine calls the Aronaxx and tells Hernandez where the Minerva is, Hernandez says he'll send subs to their position. As Ant eavesdrops on Conger and one of his men Conger finds an item which turns out to be another piece of the Ephemychron shortly after he receives a call from Hernandez who turns out to be working for them.
Hernandez tells Conger that the children have found the Minerva and that the artifact must be secured or their employer will be very unpleased, Conger orders his men to capture the children and they head out and chase after Fontaine. Pyrosome returns to question Will and Kaiko further when Kaiko notes to her how its odd that Hernandez found both the tracking logs and the stolen painting, immediately after Hernandez sets off an alarm on the bridge which brings the three to it as a distraction and then breaks into Will's safe stealing their piece of the Ephemychron before escaping in a sub. Will finds the last coordinates on the computer and they move to it. Back on the Minerva Ant tells Fontaine that Hernandez is working for Conger but Hernandez joins in on the chase shortly after and Conger hears Fontaine yelling over the radio and captures Ant.
Conger tells Ant that he was the salvage company that hired the Nektons to begin with and that he plans to take the Minerva aboard his sub strip it of everything valuable and then dispose of it afterward. Conger's sub arrives and attaches magnetic clamps to the Minerva and starts to lift it but one of his men accidently crashes into one of the cables making the Minerva shake, this allows Ant to escape and get back in the Shadow Knight where he takes Conger's piece of the Ephemychron with him, he then leaves to help Fontaine outside and rams Hernandez's sub disabling it and then deals with the rest while Fontaine cuts the cables with the Rover's laser freeing the Minerva. Conger leaves the Minerva to try and get the piece back from Ant but Ant damages his subs canopy forcing him to retreat back to his ship, Hernandez escapes his sub with the stolen piece and joins Conger, Fontaine is able cut the Minerva free and Conger is forced to flee just as the Aronaxx arrives.
Back on the Aronaxx Will and Kaiko are relieved to see Ant and Fontaine safe and Pyrosome says that the W.O.A. will make sure the art on the Minerva is protected, then one of the guards shows Pyrosome the real painting of "Child with Kraken" and tells her the one they found earlier was a fake planted by Hernandez. Pyrosome apologizes for the whole misunderstanding and she and her men leave but not before Fontaine gets a picture of the painting. In the study Will is distraught over losing the Ephemychron piece but Ant then shows him the piece he found, this encourages the others more then ever that they can find Lemuria, Fontaine then pulls up her picture of the painting which shows the Ephemychron in whole being held by young individual, as Ant looks down at his piece the others notice shockingly similar appearance between him and the figure in the painting.
- This is Commander Pyrosome's only appearance in the flesh all of her other appearances are on computer screens
- This is Conger's last appearance to date.
- This is the first mention of Fontaine's room though it has still yet to appear on screen.