Agatha Christie 
Tape Measure Murder [EPUB ebook] 

Miss Politt has been waiting and waiting outside Laburnum Cottage for Mrs. Spenlow, to no avail. She nervously acquires the help of her next-door neighbor, whose gumption and persistence reveal that Mrs. Spenlow is dead on the hearthrug. The whole of St. Mary Mead is convinced the murderer is Mr. Spenlow, who shows no emotion upon his wifes sudden death, but, with characteristic diligence, Miss Marple reveals that it is perhaps not that simple.