After a violent attack on Denis Brooks,
organist in the small
cathedral city of Tolnbridge in
Devon,
Gervase Fen sends a
telegram to his composer acquaintance, Geoffrey Vintner, urging him to hurry down to take over his duties. Before he has even left London, Vintner is attacked by an unknown assailant in a
department store and has another narrow escape while travelling down on the train from
Paddington. In Tolnbridge, Vintner is put up in the cathedral’s
clergy-house, and is introduced to a large group of variously eccentric ‘cathedral people’. Brooks has been in hospital ever since the attack, and that evening his medication is tampered with and he dies from
atropine poisoning. It seems that he may have been silenced after seeing something in the cathedral. The police suspect that an enemy
spy ring has been transmitting from the cathedral at night, using a portable
wireless transmitter. Later that night, while Fen and Vintner are outside the cathedral, they hear a mighty crash. Dr Butler, inside, has been killed by a falling stone slab that marks the entrance to an ancient tomb. Sir John Dallow, the cathedral’s
Chancellor, tells Fen and Vintner of 17th century local
witch trials. Vintner has fallen in love with Dr Butler’s daughter, Frances, and impetuously asks her to marry him. Few of the potential suspects have alibis for the murders, and Fen eventually closes in on the culprits by a close consideration of the group’s movements and timings. Fen and Vintner attend a
black mass, and are attacked by the masked
celebrant. The gang is eventually revealed to include the young curate July Savernake and the landlord of the local pub, Harry James. Their ringleader is Frances Butler, unexpectedly revealed as a
Nazi sympathiser and
Devil-worshipper. Her motives are not easy to understand, and Sir John Dallow speculates that it may have been in her blood: as a member of a very old local family, the evil of witchcraft may have been passed down to her through the centuries. == Principal characters ==