The Rugrats find themselves stranded on a deserted island after their tropical cruise ship is flipped over by a rogue wave. As they navigate the unfamiliar terrain, they meet the Thornberry family, who agrees to help them escape in exchange for their companionship. With the kids setting off to find Nigel, while Eliza and Darwin search for Spike's lost babies, chaos ensues as the two families' paths cross, leading to a series of hilarious misadventures.