London, 1670: Commissioned to design a new house for the merchant Francis Polegate, Christopher Redmayne is pleased that everything has gone without a hitch. To celebrate the success of the venture, Polegate throws a party, but it comes to an abrupt end when one of the guests is murdered on leaving the house... With blood staining the doorstep of his new creation, Redmayne can't help but feel involved, and with the help of his good friend, the Puritan Constable Jonathan Bale and his dissolute brother Henry, Redmayne vows to find the killer and bring him to justice.