To find a piece of the mysterious Ephemychron, the Nektons have to fight off whirlpools, zero visibility and giant robotic jellyfish! Is Nereus doing this to them? If not, who is really behind all these obstacles?

Ant and Fontaine hunt for one of the rarest ocean creatures, the colossal squid. But it turns out to be smarter than anyone thought and thinks the Nektons look tasty! Can the Aronnax survive being pulled down very, very deep?