The Victorian home of the proper Miss Letitia Blacklock hardly seems a likely setting for a crime.  So when a mysterious advertisement in the local paper announces the exact date and time a murder will take place there, the mistress of the house can only imagine it must be a silly prank.  Of course, it's not.  Luckily, the indefatigable Miss Marple is on hand to help the local inspector tackle one of Agatha Christie's most fiendishly ingenious and deadly puzzles of mixed motives, long-buried secrets and concealed identities.