The Conspiracy Club - Jonathan Kellerman

When psychologist Dr. Jeremy Carrier's romance with nurse Jocelyn Banks is cut short by her kidnapping and brutal murder, he is left emotionally devastated and being watched by police seeking a prime suspect in the unsolved killing. To escape the pain, he buries himself in his work. But when more women turn up murdered in the same gruesome fashion, the suspicion surrounding Jeremy intensifies and the only way for him to prove his innocence is to follow the trail of a cunning psychopath. Spurring on Jeremy's investigation is Dr. Arthur Chess, an enigmatic pathologist who draws Jeremy into the confidence of a cryptic society devoted to matters unknown and unspoken. But when Arthur suddenly slips away, Jeremy is left to contend with an onslaught of anonymous clues - and the growing realization that a harrowing game of cat and mouse has been started.