In the Aegean a large airplane crashes at almost the same time a luxurious yacht is sinking. Commander Talbot of the Ariadne, a sophisticated British ship that is part of NATO, picks up the yacht's survivors, among them a wealthy Greek businessman. The downed plane, it is learned, contains hydrogen bombs and atomic mines, one of which is ticking. If the mine explodes in that spot, earthquakes, volcano eruptions, tidal waves, ozone cracking, and possibly the end of the world could ensue.