Bitter Night (The McLaren Mysteries, #20)

When former police detective Michael McLaren is given an old photograph and newspaper article, an inquiry begins that seems straight forward enough: an accident in a millpond. But when it's apparent that other odd deaths are linked to this, all via the victims receiving a cypher puzzle, the secret meanings become more important. More important still when a fifth death occurs practically on McLaren's doorstep.

Now it's five deaths and five puzzles, and McLaren's determined to solve the myster...