What was Prince Ludovico Ruspanti doing in the Vatican when he fell to his death in the chapel at St Peter's? Did he fall or was he pushed? The papal authorities contacted the Criminalpol, and as Inspector Zen probes into the scandal he finds witness after witness mysteriously silenced by violent death What is the secret of the Vatican and who is behind these killings? The answer is elusive, and Zen knows he will never find it until he penetrates the most secret of all secret societies, the Cabal