After the catastrophic result during a fast race between Yakari and Rainbow down the river, the two friends try their best to help the beavers rebuild their dam. But in the meantime, the mischievous little rascal, Linden, takes Rainbow's raft for a quick ride, unbeknownst to him that he is heading towards the dangerous rapids. Unfortunately, as Yakari tries to save Linden, they will get trapped in a small and gloomy cave with steep walls. Will they find a way out of there?
—Nick Riganas