Cap'n Turbot is taking Francois, Mayor Goodway, Julius, and Julia through the swamp on the Flounder. However, when they stop for lunch, something spooks the twins. Mayor Goodway chases after them, but ends up stuck in quicksand. Meanwhile, Cap'n Turbot loses his cellphone in Francois' soup, and the twins are able to use their aunt's phone to warn Ryder.
At the Lookout, Ryder gets the call for help, and summons the pups to the Lookout for an Ultimate Rescue mission. As they head up the elevator after Marshall's usual shenanigans, the PAW Patrol shield changes to Zuma's badge, and the pups are suited up in uniforms decked with camouflage. Ryder appears sporting a similar uniform, and after briefing the pups, assigns Zuma as team leader. Zuma then heads down the slide and upon landing in his hovercraft, he is taken down to the underground maintenance area to have his hovercraft upgraded to its Ultimate Rescue appearance, which appears similar to an airboat. Once the pups load up, and Ryder deploys on his ATV, painted orange for the mission, they head for the water. Ryder converts his ATV to hovercraft mode, and they head towards the swamp.
Once there, they locate the Goodways thanks to Chase's swamp drone UAV, and carefully help Mayor Goodway out of the quicksand and return them to the Flounder. Soon, the monster that spooked the twins appears, but Zuma realizes its a very big catfish, which has become stranded in the swamp due to the tide receding and the water level dropping, and using his inflatable rescue boat, and a little of Francois' broccoli soup, they get the catfish on board and head for the open water.
However, on the way, the Flounder gets stuck on some of the exposed tree roots from the receding tide. With a little help from Zuma and Rocky on their deployable jet skis, they get the ship free, and after Skye helps scout ahead on her swamp glider, they get the catfish back to open water.
As everyone celebrates, Cap'n Turbot hears his cellphone, which is soon burped up by the catfish. However, the Cap'n has some trouble trying to get a good grip on it as it keeps slipping out of his hands, much to the amusement of everyone else.