Sailing in the Aegean, NATO spyship HMS Ariadne sights two disasters at once, a bomber crashing into the sea and a large yacht sinking. The plane turns out to have been loaded with nuclear weapons, and the survivors rescued from the yacht appear somehow responsible for the plane's destruction. With potential saboteurs aboard, the crew of the Ariadne must raise the one activated weapon and carefully dispose of it. MacLean (The Lonely Sea has trumped up so many aspects of this novel that he has taken the fun out of it. Rather than have the spies seized and flown off, he keeps them on the frigate. Instead of bringing in experts to remove the weapons, he leaves the job in the hands of the ship's captain. He also ups the stakes: if the unstable nearby volcano, Santorini, erupts, the combined explosions would create a nuclear winter. The contrived plot together with MacLean's stiff writing style make for a lazily composed adventure.