The Dark Orca pirates attack, they believe the Nektons have treasure aboard their sub.
An artificial intelligence programmed to run the sub and protect the Nektons tries to stop their rescue mission because it's too risky.
The object that Will and Ant are retrieving from the deepest part of the ocean is not what they expected.
Are aliens stealing things from a Japanese island and dragging them underwater? The Nektons investigate and find something even more dangerous and amazing!
Someone stole the rarest tortoise in the world and the Nektons are searching for it.
Captain Hammerhead captures the Nektons aboard his submarine! But when his sub begins to sink, only the Aronnax can help.
To find a piece of the mysterious Ephemychron, the Nektons have to fight off whirlpools, zero visibility and giant, robotic jellyfish.
The Nektons explore an underwater cave system inhabited by huge, prehistoric crocodiles. Ant befriends a new hatchling, much to the annoyance of its mother.
Ant and Fontaine hunt for the rarest of ocean creatures, the colossal squid. But it turns out to be smarter than them and thinks they look tasty.
The Nektons meet online superstar Devil Daniels, who will stop at nothing to reach the fame that he seeks.
Ant believes that a ghost sub is at sail somewhere out in the ocean - but when he actually finds it, the truth is even stranger.
While diving into a rare 'blue hole', a sinkhole in the middle of the sea, strange things begin to happen to the Nektons.
Ant and Fontaine have to deal with young fans visiting the Aronnax when they have to rescue a whale calf.
Dolos has sold two maps leading to the same treasure - one to the Nektons, the other to the pirates! Now it's a race to get there first.
As the Nektons explore a mysterious tunnel behind a huge undersea waterfall, strange creatures and strong currents surprise them at every turn.
The Nektons are arrested for stealing. Ant and Fontaine escape to prove their innocence, but whoever set them up is already two steps ahead.
Fontaine and Smiling Finn get stuck inside a giant clam as the dark orca pirates battle the Nektons for the giant pearl within.
Proteus, leader of the mysterious Guardians, traps the Aronnax in a magnetic field and kidnaps Ant, believing he is the key to finding Lemuria.
Devil Daniels, Monster Hunter, attempts to hunt a sire - a mythical creature whose song lures sailors to their doom.
A fish invades Jeffrey's home on the Aronnax. How can she get rid of it and its bad luck?
The Rover is swallowed by a huge prehistoric shark. Will and Fontaine manage to cling to its gills just inside its mouth.
The Nektons are trying to identify a unique life form. They've never seen it, they've only heard its sound: 'Bloop'.
A weird glowing fish has lured every fish in the area to its bioluminescence, and Kaiko and Will also fall under its spell.
While fighting over Viking treasure, the Nektons take over the Dark Orca. But the pirates in turn take over the Aronnax.
The Nektons explore a floating island and find the final piece of the Ephemychron in a cave. But the island has a terrible secret.
Is the Baltic Sea anomaly really a UFO that crashed into the ocean 600 years ago? Ant thinks it is. But what the Nektons find inside is even more strange and frightening.
The Dark Orca pirates unwittingly steal a treasure that can awaken a Monumential and possibly destroy them and the Nektons.
The internet being down is the worst thing imaginable for Ant and Fontaine - until Ant finds the sea monster responsible! Can he save both?
Trying to rescue Jess Gorman in an underwater cave proves dangerous for Ant and Fontaine until a Manatee comes to their aid.
The Aronnax and Alpheus' sub are trapped within a giant Jellyfish Monumential. They've been eaten and the jellyfish won't let food out.
Devil Daniels insists he's relocating a dangerous killer whale. But it is a scam that turns dangerous - for Ant and the whale.
The Nektons find an underwater crop circle. It's made by a giant male puffer fish to attract a mate. Can Ant help the romance along?
Ant tries to locate a "diamond-horned sea-unicorn" as a present for Fontaine's birthday. But Dolos and Devil Daniels are also hunting it.
The Nektons try to save an island from "The Purple Tide" that legend says will destroy everything. To save it, they need to find "The Protector".
Ant wants to go faster than the fastest fish in the sea - the sailfish. But he hasn't counted on a deadly oil spill.
Jeffrey is kidnapped, in his "Jeffrey Knight", by Dark Orca pirates. Can Jeffrey turn the tables and save himself?
The Nektons return to the mysterious Lemurian Gates they found previously. Exploring within, they're stunned to discover Lemuria is here.
The Nektons explore Lemuria but Fontaine realises the others are being affected by a dangerous algae. Can she find an antidote and save them?
The Nektons find the Queen's sceptre. But when faced with the Kraken and the Electric Ray Monumential together, Ant can't make it work.
Ant and Fontaine realise their grandparents found Lemuria before them - but where are they now?\n\nThe Nektons follow the trail they left but run into giant, predatory Sand Strikers! Was this the fate of their grandparents?
Ant searches a deep chasm for clues to his grandparents' fate but is stunned to find Mad Madeline there! She has been looking for the biggest sunken treasure ever, but all she has managed to find is the biggest monster!
Three baby Monumential turtles hatch, and they are the size of city blocks! The playful babies accidentally sink a fishing trawler! Can the Nektons wrangle these creatures before they sink even more ships?
Does Dolos really have a lead on finding Ant’s grandparents? Or is he leading the Nektons into a dangerous chasm between moving tectonic plates for nefarious purposes?
A mysterious dolphin in a sophisticated electronic harness zaps all the Rover's power! Ant and Fontaine manage to remove the harness, but can they rehabilitate this cybernetic dolphin to survive in the wild?
Mad Madeline steals the dangerous Sceptre of Queen Dorius.
The Nektons help locate a legendary Singaporean glass cabinet. However, they discover it is guarded by a terrifying and familiar creature.
The Nektons are busy recovering sunken shipping containers, so when Bethany the fish finds herself in danger, only Jeffrey can save her!
Ant has created a clever machine to clean up a vast oceanic rubbish dump. However, when the machine is been eaten by a huge creature, it's up to the Nektons to save it.
Ant and Fontaine discover the secret of the Bajau Laut people, a tribe of sea nomads living in the South China Sea. The pair are determined to help them - but how do you find a fish that walks?
Ant and Fontaine rescue a polar bear from the middle of the ocean. However, when they bring her onboard, they realize she is close to giving birth! Can the Nektons move her to a safer place in time?
Fontaine is amazed when Smiling Finn tells her that he has detected a signal from her grandparents’ missing submarine. Is this a joke, an elaborate scam, or something even more amazing?
A submarine is trapped in an astonishing location! The Nektons launch an elaborate and dangerous rescue mission to save the people inside. Could it be their missing grandparents?