On their way to Hawaii for a race, the kids relax on Uncle Zachary's boat. Dan is enjoying some waterboarding when a playful dolphin knocks him into the water, and Tess and Daisy make fun of him. Uncle Zach calls, alerting them of a coming underwater eruption that will trigger a massive tidal wave in their area. They've got to warn a Dr. Mark Lungo, a genetic engineer creating new species of animals on a nearby island. Lungo can't seem to be reached by radio, and he will only talk directly with Uncle Zach, so Zach programs a recognition code into Wheels so the doctor will know he sent them. As the kids approach the island, another ship orders them to leave, warning them of "severe consequences". Kuma goes nuts upon hearing the voice, just like he did when Zach flashed Lungo's picture flashed on the communication screen.
The team leaves the boat, taking Roadie and Wheels in hydrofoil mode to the island, but Wheels hits a mine in the water, which damages him and wipes out the recognition code. Dan heads off to try his luck with Lungo anyway, but refuses to bring Kuma, who's been acting even weirder than usual lately. Tess gets to work fixing Wheels while Dan and Roadie hack through the vegetation to Lungo's compound. A man who has been watching the kids approaches Tess and identifies himself as Ferris, one of Lungo's assistants. He warns her that the doctor is insane and has prisoners locked up on the island, so they take Wheels to go free them. Dan meets Lungo, riding a horse with ibex horns, and tries to explain what's happening, but without Uncle Zach's code Lungo doesn't believe he's really from Pole Position. Dan gets smart-alecky but quickly regrets it as Lungo's two other assistants, Mike and Gene, grab him, necessitating a smoke-screen rescue from Roadie. Ferris leads Tess to a pyramid within some ancient ruins, but they find no prisoners, only Lungo's research papers, which his assistants plan to steal. Tess, Daisy and Kuma end up trapped inside the flooding chamber with a hungry barracuda.
Dan arrives back at the beach and finds his sisters gone. He is attacked by Lungo's pet bird, a cross between a falcon and a vulture. Tess fends off the barracuda and gets Daisy and Kuma out through a hole in the ceiling, but Tess herself won't fit. Daisy is able to get help from Wheels, who enlarges the hole so Tess can climb out. Meanwhile Dan is still struggling to straighten out the misunderstanding with Lungo, until an earth tremor signals the impending tidal wave. Dan decides to cut his losses, find the others, and clear out. Roadie follows Wheels' heat trail through a path lined with dart-shooting statues, and they meet up with the girls. Tess is determined to finish the job they were assigned, but both cars soon become trapped in another ruin with the ceiling lowering to crush them. They are saved in the nick of time by, amazingly, Lungo himself. When the good doctor sees Kuma, he realizes they really were sent by Dr. Zachary... in fact, Lungo is the man who created Kuma! The island used to be his home, that's why he's been acting so excited. Lungo explains that the tribe that once lived on the island built the trap-laden ruins, and Lungo simply used them to protect his research papers... which are currently being taken off the island by his assistants. The kids investigate an explosion from the beach and see that their ship has hit a mine and is sinking. They hydrofoil to it, saving Lungo's scattered research papers and capturing the traitorous assistants, but the tidal wave is right upon them! Roadie and Wheels' grappling hooks barely manage to pull everyone up the side of a mountain cliff, just out of the wave's reach. To show his gratitude, Lungo offers to make them another Kuma, but Tess, witnessing their pet's latest antics, comments that one Kuma is plenty.