Clemency Shaw, the wife of a prominent doctor, has died in a tragic fire. But whether the blaze was set by an arsonist aiming for the doctor, or set by the doctor himself, Pitt is not certain. With the scarcity of clues, Pitt turns to Clemency’s stuffy but distinguished relatives. Meanwhile Charlotte retraces the dangerous path that Clemency walked the last months of her life, and finds herself enmeshed in a sinister web that stretches from the lowest slums to the loftiest centres of power…