In their ninth recorded case, indomitable detectives Arthur Bryant and John May (still going strong after a partnership of some seventy years) and their team at the Peculiar Crimes Unit must solve the murder of a toddler who, evidence suggests, was the victim of an antique Punch doll. In a side plot, the woman assisting Bryant with his memoirs, which touch on sensitive national security issues, has also died mysteriously and her files have disappeared. A gruesome theatrical murder mystery and a replica of a medieval torture chamber also play a part in the case and its solution. As usual, there is never a dull moment with irascible, eccentric curmudgeon Bryant ("We're old. We can do whatever we like.") and his foil, dapper ladies' man May on the job.