In the early morning hours of March 18, 1990, two men dressed as Boston police officers gained entry into the Isabella Stuart Gardner Museum and pulled off the largest art heist in history.To this day, none of the pieces, including works by Rembrandt, Degas, and Manet, have been recovered, and no arrests have been made. The stolen artwork's estimated current value is $500 million dollars.Is it possible these thieves were actually caught by the police weeks after the crime, but a cover-up was put in place to hide the truth? What if a 21-year-old pact between the arresting officers and the thieves started to unravel? What if one of the criminals shared this reality with his psychologist for self-serving reasons, triggering a deadly chain reaction?This is the premise of William Nolan's The Therapist.