Unaware that two of his treasure-hunting friends are trapped inside, Mike sets charges to blow up a sunken ship that is a menace to a busy shipping lane.

While on a diving expedition in Guatemala, a woman seeking to slow down her husband's frantic lifestyle deliberately sinks the boat they share, unaware that her husband is a diabetic and his insulin supply will be lost with the vessel.

Mike helps the daughter of his old UDT Commander investigate the man's death, which she believes was murder.