Dr. Kep Woodhead is a brilliant, irascible forensic toxicologist with a dark past. Bernadette Becker is a disgraced federal investigator with one last chance. They're both assigned to a strange poisoning case: a graduate student has been found dead in a 15th-century chapel, a needle filled with a controversial hallucinogen sticking out of his arm. The priest, the professor, the piscary president, the protestor, the protege - they all emerge as suspects to stop the victim's research project, and soon Becker's life is in danger. Do Becker and Woodhead have a prayer of discovering the truth before more people are killed?