This book is set in London in the spring of 1663. This is near the beginning of the Reformation when all of the United Kingdom is trying to get over Cromwell's Puritan reign. Charles II is back as monarch, and he and his entourage are involved in all kinds of intrigue. The quarrel between the Earl of Clarendon and the earl of Bristol was at its height at this time, and there is more than enough work for Chaloner as he spies for the Earl of Clarendon. It is also a time of great public interest in the science of disection. Barber/Surgeons went to great lengths to get the cadavers that they required for their studies. Chaloner finds himself in the middle of intrigue, body snatchers, and murder and mayhem.
The best thing about Ms. Gregory's books is the historical fact that she builds her fiction around, and that is very apparent here. She makes Restoration England come alive under her pen. This is not an era that has a lot of fiction built around it, so it is interesting to see what life was like then.