When Hell freezes over, anything can happen... SOMEWHERE above the Arctic Circle, three hundred feet below the icy surface, two American nuclear-powered submarines disappear. In fact, they melt. SOMEONE is turning on heat in a way that it's never been turned on before. SOMEHOW, Intertrust's top agent, MARK HOOD, has to find answers, and fast. Fortunately, his first clue is a beautiful, bed-able blonde. Unfortunately, she is also exquisitely lethal. And quite coincidentally, Mark Hood suddenly finds himself in a Viking fortress, playing an integral part in a bizarre plot to destroy the world....
Used availability for James Dark's Operation Ice Cap
May 1969 : USA Mass Market Paperback