Thirteen-year-old Caleb Weybourne is sent to spend the summer with his archaeologist father in the remote town of Chismo in northern Canada, where Professor Weybourne hopes to prove the existence of the Mahkneejosh, the legendary great lake monster of the native Ojibway people. In Chismo, Caleb befriends two Ojibway boys, Isaac and Eli, and a colourful old Ojibway man, Emmett. On a fishing trip to Red Marsh Lake, the boys encounter the violent and dangerous local fugitive, Kibo, and almost lose their lives. During their fight from him, Caleb believes he may have seen the mysterious water monster...