Michael goes to a beach to test K.I.T.T.'s new "Aquatic Synthesizer" which allows him to drive on water. He aborts the test when KITT discovers a body of a young diver named Bobby Shell who is alive but suffering from the bends. Michael rushes him to a hospital where he meets his sister, Jennifer. Michael looks over the boy's diving gear which has clearly been sabotaged, and also finds a solid gold Aztec coin. Michael further investigates down at the shore and discovers the fishing vessel Fin Quest, which is supposed to be part of an aquatic research project, is captained by a man, Zachary Sloate, a ruthless treasure hunter. Devon informs Michael that Sloate is obsessed with finding an Aztec statue called "Nacinda". After another attempt is made on Bobby's life, Bobby confesses that he had