When Hodgkiss decides to join an exercise group run by a very attractive young woman his daughter, Esme, insists that his friend Pat Strong join the group as chaperone. Hodgkiss soon learns that the notoriously corrupt Kanundda Council has plans to redevelop the park where the classes are held, plans that will greatly enrich the mayor and his cronies. But these plans are doomed because there is a murderer among the exercise group who commits his crime under cover of one of the exercise routines.
When mail is delivered to the wrong addresses there can be serious consequences, as Hodgkiss discovers when his friend Pat Strong receives such a misdelivered letter. When they start to backtrack on the letter's history they find themselves on the trail of a ruthless psychopath who has killed to gain control of what he believes will be a valuable mine.
The Mayor of Kanundda hires a killer with a strict code of honour to murder a public servant who is about to recommend that Kanundda Council be abolished. Hodgkiss, who bears a striking resemblance to the murdered man, manages to convince the mayor that the killer has not done the job and soon the mayor and his hired assassin are in savage disagreement.