The episode opens with the campers escaping in the Yacht. They express relief that they are finally going to get to go home. Brooklynn visits Kenji as he attempts to steer the boat, convincing him to join the children for a meal. As the children sit down to eat, Ben serves them all grubs, Sammy starts to try to eat one of them but cant bring herself to do it. Sammy exhorts them all to stay in contact and trade contract information.
Kenji and Ben note their food going missing, and they realize that a Compy has snuck on board the boat. The group attempt to chase the compy, as Kenji heads back to the control room , determined to try and steer the boat towards home. Brooklynn goes to talk to him, as the other campers try and fail to catch the Compy.
The Compy evades them, leading them to attempt to search the cabins. Brooklynn helps Kenji in the control room, just as the boat rocks due to an impact. Brooklynn helps Kenji fix the sonar, as Kenji assists her with the tools. Brooklynn admits that her father taught her how to be handy with tools, and she and Kenji bond over their shared experiences.
Sammy and Yaz search the cabins, and Yaz presents Sammy with a drawing of the group. Darius chases the compy to the deck. Brooklynn and Kenji manage to get the sonar to work and embrace, as Brooklynn confesses she’ll miss him. The Compy is cornered by Ben, Sammy and Darius, who almost trap it before the boat rocks yet again. As Kenji turns on the sonar, they determine the propeller is jammed and someone might need to go down and loosen it. Darius volunteers to perform the task.
Darius connects himself to a rope and dives down into the water to free the propeller. Darius frees the propeller, while Kenji tries the engine and gets it to work. Meanwhile, the sonar ping indicates something large is headed their way. As the group attempts to pull him back in, Kenji sees a shark on the telescope, Darius gets his foot caught on kelp, and the rope snaps. Just as the group panics, there is a much larger ping on the Sonar, as the Mosasaur appears and swallows the Shark whole, before pursuing Darius.
Kenji jumps in the water to rescue Darius, and successfully manages to grab him and swim with him back to the boat. The Mosasaurus pursues the pair of them, as they hang onto a life preserver and just barely manage to get onto the boat. Brooklynn attempts to steer the group away from the animal, they believe themselves to have escaped, but then the Mosasaur rams the boat again. The Mosasaur succeeds in biting down on the boat, causing it to start to capsize.
As the Boat begins to sink due to its attack, Kenji has no choice but to direct the boat to an unknown area of land in front of them. The Mosasaur leaps out of the water and slams back down on the boat, destroying the boat. The campers wake up on an isolated shoreline, as the campers take shelter in a nearby cave.