Thea Hahn is a highly gifted child, exceptional in mathematics, astrophysics and chess. But Thea has disappeared, and her chilly parents are very worried and want their sixteen-year-old daughter back home. What they don't want is any fuss, any embarassment, so they hire Anna Lee to find her. When Thea turns up, however, she seems deranged and is raving about murder. Soon, she becomes the prime suspect in a very nasty killing. Anna knows she must win Thea's trust and find a way into her brilliant, disturbed mind if she is to be saved...