'Although seven clowns started the evening alive, only six still breathed by the evening's end. And while everyone saw the murderer and knew the murderer, no one knew their name.'

Henry House, an Elizabethan manor, is now occupied by Mind Gains, a new therapy centre in Stormhaven. But a Halloween party for staff and clients ends in gruesome and bloody murder. Once again, retired monk Abbot Peter and his niece Detective Inspector Tamsin Shah are called upon to solve the mystery.

Who could have reason to kill the mild-mannered therapist, Barnabus Hope? What did he know that he shouldn't? As the Abbot and Detective enter the darkness, they find a therapy centre with much on its mind; and as staff and clients come under suspicion, Henry House proves reluctant to hand over its haunting secrets. Are there clues in the writings of a 14th century Persian poet? Maybe. But the psychology of horror must first have its day.