Almstone Manor is a fine old Tudor manor in Calleshire, England, set aside years ago as a rest home for members of a military regiment - the Fearnshires - and their families. Since most are in poor health during their time at Almstone Manor - as Gertrude Powell certainly was - it is no surprise when one of the residents dies. But Gertrude Powell is different - a letter to her son, mailed by her arrangement after her death, claims that someone is out to kill her.
Receiving the letter on the day of her funeral, Gertrude Powell's son brings it to the attention of Detective Inspector C. D. Sloan. First, Sloan must stop the funeral in progress. Then he has to investigate Powell's posthumous claims. Is the letter just the ravings of an ill, somewhat melodramatic woman? Or is something very sinister going on at Almstone Manor, whose residents have known each other for more than fifty years and some of whose very old grudges may run very deep indeed...
All the way through the book, it has seemed familiar to me but not enough to recall what was going to happen next until after I'd read it! And I didn't have a clue who-dun-it either. :(
The next one on the list is #18 "Little Knell" of the 21 books in her series that I have. I'll probably start it tomorrow but not finish it until after I've read "At All Costs" by David Weber.