A bishop visiting St Gerard's College is found dead after drinking poisoned wine; Lewis and Hathaway suspect that she has been killed because of her progressive views. When another two killings occur, both mirroring macabre murders from a Jacobean revenge tragedy, it appears the murderer is targeting candidates for the post of vice-regent of the college. However, after learning that one of the suspects harbors a dark secret, Lewis and Hathaway realise the motive is much more twisted and that the murderer is avenging perceived slights from over twenty years before.