Death in Summer by William Trevor

From the winner of the 1999 David Cohen British Literature Prize comes an unforgettably chilling novel, written with the compassion and artistry that define Trevor's fiction.

There were three deaths that summer. The first was Letitia's, sudden and quite unexpected, leaving her husband, Thaddeus, haunted by the details of her last afternoon.
The next death came some weeks later, after Thaddeus's mother-in-law helped him to interview for a nanny to bring up their baby. None of the applicants were suitable--least of all the last one, with her sharp features, her shabby clothes that reeked of cigarettes, her badly typed references--so Letitia's mother moved herself in. But then, just as the household was beginning to settle down, the last of the nannies surprisingly returned, her unwelcome arrival heralding the third of the summer tragedies.