Twenty-One Days is the start of a new series for Perry, one that is deeply rooted in what has come before. This one is set in Edwardian England in 1910 and features Daniel Pitt, the son of Charlotte and Thomas.
As the series opens, Daniel is a young barrister acting as the solo defense attorney for a client for the first time in his career. Before that case even finishes, Daniel is assigned another case that doesn't go as well. The client, accused wife-killer, Russel Graves, is found guilty and sentenced to hang. Daniel now has 21 days to find the real killer and keep his client alive. He's assisted by a ragtag group of people, including Miriam Fford Croft. Miriam is his boss's daughter and has been fully trained in chemistry and medicine but unable to get a degree because of her gender. She teams up with Daniel in solving the crime.
Because this is a first in a series, Perry takes a fair amount of time (and page space) to introduce the cast of characters, so the mystery is not as complex as it could have been. That said, this was a solid new entry into the historical mystery realm, and fans of Perry will find a lot to love here.