Katie McDonald 03-Serial Killer Sudoku

3. Serial Killer Sudoku (2009)

Kate has settled into her new life running the Avondale Puzzle Museum in Granville, New Hampshire, and the locals have begun to accept her presence. 

When the new owner of the local newspaper begins to cause a panic by suggesting that a Boston serial killer is headed to Granville, Katie and police chief Brandon Mitchell try to quash the rumors. However, when an unpopular resident is found murdered, and Katie begins to receive messages from the killer in the form of Sudoku puzzles, she becomes immersed in the investigation. Her involvement deepens when Brandon is injured and can no longer lead the hunt for the killer - the same killer who leaves a puzzle at each crime scene, and is now focused on Kate…

At the same time a former partner of Police Chief Brandon’s shows up with information about the killer who has just struck Granville and put the Police Chief out of commission. Assisted by Brandon’s 14-year-old ward, Harry, Katie works at solving the crime, with Brandon’s help in the final hour.