As the episode opens, the pups are on the beach enjoying playing with an inflatable toy shaped like a dolphin and enjoying themselves very much.
Elsewhere, we see Cap'n Turbot and Wally on the lookout for a dolphin family and their newborn pup as the Cap'n can't wait to see it. The pup just so happens to pop up next to Wally, but the Cap'n doesn't notice at first as he mistakes the pups' toy for the pup until he finally decides to turn to look at Wally. To show his absentmindedness, the Cap'n tells Wally not to move as the pup is right next to him, leading Wally to face-palm in annoyance. The pup enjoys herself, until a flock of geese fly overhead, causing the pup to head for the mouth of the river and head upstream. Worrying for it, the Cap'n quickly gets on the phone to warn Ryder.
Ryder gets Turbot's call, and while the Cap'n accidentally gets Ryder and the pup mixed up in his call for help, once he tells Ryder of the situation, Ryder assures that the PAW Patrol is on their way and summons the pups.
The pups are still playing over who gets the toy and bringing it back to the Lookout, when Skye gets it and brings it back. When they reach the Lookout, Marshall is knocked back out of the elevator by the toy before the doors close, leaving the toy to end up being decked out in Marshall's fire helmet and vest as it heads up to the top of the Lookout. When the toy lands where Marshall should be in the lineup, it leads to puzzlement from the other pups before Marshall is heard, and seen, struggling up Ryder's fire pole before grabbing onto the floor of the Lookout as he catches his breath and says Chase's usual line of reporting for duty, leading to laughter from the other pups. Afterwards, Marshall is back in uniform and back in line, Chase says his line, and Ryder tells the pups of the situation with the dolphin pup, which Rubble mistakes for being him due to an upset stomach earlier. Afterwards, Ryder hands out the orders: Chase will go upstream to set up a roadblock to keep the pup from going any further inland, while Zuma will help Ryder in trying to get the pup back out to the ocean and it's family. The team deploys, and taking a shortcut around Katie's Pet Parlor, all three vehicles go airborne before Ryder and Zuma hit the water, and Chase bounces his truck down on the opposite shore.
Chase soon reaches a choke point in the river and deploys his net to block it off. As for Ryder and Zuma, the pup soon appears to spit water in Zuma's face, then does it again, indicating that instead of returning to it's family, it just wants to play. Realizing that they can use the inflatable toy to lure the pup back to the ocean, Ryder quickly contacts Skye about it after getting word from Chase that the pup is now at the choke point, and is busy chasing a butterfly around the small rocks there that could cause it to become trapped. When Skye gets word of the need for the toy, she and the others have not seen it since the incident in the elevator with Marshall's gear, but Rocky realizes it must be in his pup house. After tossing a few things out, including the head of a mop and part of Marshall's Halloween costume that end up on Marshall's head, Rocky emerges with the toy, but his teeth puncture the tail, causing the toy to deflate before landing on Marshall. Rocky relays the bad news to Ryder, who reminds Rocky to use his pup-pack to mend it, quickly perking him back up. After placing a small patch over the puncture to seal it up, Rocky uses a homemade air pump to re-inflate the toy. Once finished, Skye airlifts it to Ryder and Zuma.
Once they get the toy, Ryder attaches it to the rope for Zuma's buoy, and they take over to where Chase is still watching the pup. Once she sees the toy and believes it to be a playmate, the pup happily follows Ryder and Zuma back to the ocean where, after dropping off the toy, Skye was dispatched to look for the pup's family so she could be reunited with them. When the pup disappears underwater and doesn't pop up again, Zuma worries the plan failed, until the pup's appearance in front of him forces Zuma to evade her, and end up driving his hovercraft off a buoy marker like a makeshift ramp, causing Zuma to be flung out of his seat, and land on the toy, hanging on for dear life as his hovercraft keeps going without him to drive it. Ryder quickly comes to Zuma's aid, setting his ATV on auto-pilot, while he leaps into Zuma's hovercraft and brings it to a stop. After Zuma gets back into his seat, he admits that he loved the ride, and he and Ryder get back to reuniting the pup with her family.
It is not long before Ryder and Zuma meet up with the family of dolphins after Skye located them, and the pup is reunited with them. The dolphins offer their thanks to Ryder and the pups for their help, with Cap'n Turbot and Wally arriving so the Cap'n can translate what the dolphins clicked into English, and they swim off together, reunited and happy. Afterwards, Ryder asks the Cap'n about what he's looking for now, and Turbot mentions a whole family of whales are migrating nearby, and he wants to see them. Wally spots the mother whale surface for a moment and tells the Cap'n, but again, Wally face-palms when Turbot again acts absentmindedly to Wally's pointing out of the obvious.
Leaving Wally and the Cap'n to themselves, Ryder and the pups return to shore with the toy, leading to where each pup (wearing only their mission vest without their pup-pack and hat) is allowed a turn riding it while it's attached to the back of Ryder's ATV in hovercraft mode, some enjoying it, some not as much. Marshall is the last to go, but gets flung off and falls in the water, only to resurface as he's juggled about by the dolphin pup, calling for help as Ryder and the other pups laugh before the episode irises out.