Who in their midst has blood on their hands? London, 1670. Commissioned to design and build a new house for Francis Polegate, a merchant, Christopher Redmayne is pleased when the project is completed without a hitch. To celebrate the success of the venture, Polegate throws a party and invites Christopher as the guest of honour. But the party comes to an abrupt end when one of the guests is murdered upon leaving the house - with blood staining the doorstep of his new creation, Christopher can't help by feel involved. With the help of his good friend, the Puritan constable Jonathan Bale, and his dissolute brother Henry, Christopher vows to find the killer and bring him to justice. With suspicions running high and the life of someone close to him in peril, this is one of Christopher's most difficult cases as he discovers that politics really can be deadly.