A secret NATO mini-battleship sinks in the North Sea. Before British Intelligence can recover the vessel, an Eastern fishing trawler has reached the spot. Sharpe believes the trawler to be a ruse, which is soon confirmed by Probe when he spots three armed guards. Leaping from the water, dolphin-style, Probe finds that the trawler is actually a disguised salvage vessel, with the inside cut away. Surmising that it intends to haul up the battleship and is responsible for the explosion which sank it in the first place, Probe sets out to blow up the trawler. Caught by an opponent wearing a deep sea diving suit, Probe manages to electrocute him and complete his mission.
- Probe aka M.A.C.H.1 is government agent imbued with extraordinary physical power and a computer embedded in his brain.
- Sharpe is Probe's boss within the Secret Service.
- Power assisted deep sea diving suit