The second novel by the winners of the 2003 National Bestseller Award has all the merits of a “[head]uzzle” and one more: it is sharply social. The detective intrigue never lets the reader or the listener go. Sometimes it seems that the police is hunting the main character, sometimes— that a totalitarian sect is, sometimes—a childhood friend obsessed with extreme thrills, and sometimes the reader is sure that the hero of “Grey Slime,” like the hero of “The Heart of an Angel,” commits these monstrous crimes himself. The resolution destroys all versions and exceeds all expectations.