"We need new blood here, Miss Braithwaite. We decay, we grow rancid. New blood, I say," Canon Millhaven went on. "But whether as transfusion or sacrifice, I do not pretend to know."

Reverend Theodora Braithwaite arrives at the rural cathedral of Bow St. Aelfric to find it a maelstrom of petty clerical politics. The parish has a history of nasty clashes between the townspeople and the clergy, and with an unpleasant new dean assuming control of the cathedral, the age-old feud is poised to re-ignite.

The spark comes in the form of a statue -- an ancient pagan idol unearthed on church property. With a face on both the front and the back of his head, Janus is the Roman god of gateways of beginnings and ends. His sudden appearance marks the reawakening of the town's interest in paganism, and proves the end of Dean Vincent Stream, who is murdered at the idol's feet. It falls to Theodora to discover who would offer such a sacrifice, and the canny sleuth is more inclined to look for enemies of the unpopular dean than for pagan worshippers gone awry.

Unfortunately, the dean's enemies are many, and Theodora finds herself confronted with a Canon of questionable sanity, squatters with revenge on their minds, and an anonymous journalist whose poison pen draws blood with every word. With the future of both town and church depending on her success, the Reverend races to find out whose grudge has led to such violence -- before it erupts again.