 Ephraim Fabricant, a doctor jailed for a string of murders that Frank Black helped solve, is wheeled into an operating room to donate a kidney to his ailing sister. As he recovers in post-op, someone posing as a nurse savagely beats the officer on guard and takes Fabricant away. As Frank and Peter try to locate him, their investigations lead them to Lucy Butler, a woman who had kept up a long correspondence with Fabricant and who now claims to be his wife. Several days later, a much weaker Fabricant is dumped at a nearby hospital, missing his second kidney. He warns Frank that there is another force at large, one which has terrified him and is now turning its attention toward Frank and his family.