Alphonse "Dave" Davecki, Superior Wisconsin's celebrated detective, is recovered from his tangle with a mad arsonist and the challenge of solving the riddle of the infamous "mystery barrels" dumped in Lake Superior back in the '50s and '60s. Now, instead of getting a rest, he finds the body of his friend Little Willie Horton floating in the icy water. With help from the lake herself, Davecki solves the murder and saves the Big lake from being sold to the highest bidder.