Churches and synagogues are being burnt and desecrated in Whitechapel and Reid suspects the same hand behind the various attacks.
Seeking the help of Jewish mathematician, Isaac Bloom, Reid's inquiries take him into the occult. Meanwhile, the all-too-brief domestic happiness that Sergeant Drake has enjoyed is disrupted by the arrival of a friend from his wife Bella's past, the mysterious and charismatic scholar, Gabriel Cain.