Tim and his friends are enjoying the summer vacation together by the lake. As they clean up their camp after a big storm, they decide to build a raft with the wood from the fallen trees and use it to get to Indian Island. There is an Indian burial ground on the island, and they have never seen it. Nobody goes to the island, and Len, who has Indian roots, is very nervous about going. As they sail towards the island, the water gets rougher, and the mood changes. The nearer they get, the more uncomfortable they become, especially when they see that they are not alone...