She was beautiful, and in her red dress she was the most conspicuous thing in sight. A light mist gathered around her - she was gone - and near the place where she had been standing a molten pit appeared.

Incredible; yet there were a dozen witnesses who saw it happen.

Dr. Palfrey, working on the case, finds he is pitted against an enemy who can kill silently, swiftly, and anonymously. His life is in danger - and perhaps even the fate of the world hangs in balance.