Troy is revealed to be still alive and captured by the humans, locked in a cage constantly getting painful vaccines from them. However, with the help of a con-artist dwarf shark named Ronny, he manages to escape and decides to seek revenge on Pi.
At the reef, Pi is a father and enjoying life on the reef with no shark. But Troy and his band of goons arrive at the reef wall and threaten the fish that in four days the water will rise high enough for the sharks to swim over the reef wall. Nerissa tells Pi that he must but tries to train the other fish to defeat Troy this time. Meanwhile, Troy threatens Ronny into following his orders by sabotaging Pi’s training and tells him in exchange, he will let Ronny go. Ronny disguises himself with a piece of kelp as a wig and false dentures on is teeth. Witnessing Pi’s disastrous training, Ronny gets an idea. He announces that the fish put on an “underwater extravaganza” saying every fish has a special skill, and by doing that, they will attract humans to protect them from the sharks. Everybody but Pi is enlightened by Ronny’s plan. When Pi confronts Nerissa about this, Nerissa suggests that Ronny perhaps “offers something you haven’t like a chance to prove themselves.” Pi retorts that he tried train them to which Nerissa responds “I suggested that you teach them to be the best they can be–not to be you.” He then shows Pi an image of the legendary Sea Dragon, which those who control it must be worthy to command it. When Pi asks him if he’s ever tried summoning the Sea Dragon, Nerissa responds “many times.”
Pi gets an idea to create a shark trap to catapult Troy out of the sea and orders the two to get him supplies. When Pi and his son Junior set up the trap, Pi orders Bart and Eddie to guard the grotto. However, Ronny overhears Pi’s trap and Troy orders him to destroy it. So Ronny tricks the reef fish that he needs a clamp for his talent show and the reef fish soon suddenly race towards the grotto and destroy the Shark Trap. Bart & Eddie report the disaster to Pi. When Pi furiously confronts Ronny, Cordelia defends him, saying that Ronny believes in them the way they are and Pi didn’t. Pi leaves sadly.