Matthew and Annie, ages 13 and 11 respectively, are abruptly thrust into adulthood when their mother dies in childbirth and their father breaks down. Wanting to keep their family together, Matthew and Annie care for their two younger siblings and do their best to decipher and work the adult world toward their goal of keeping the four siblings together in their house.
Incoherent murmurings of their father lead them to believe he had been having an affair with a housewife with a reputation from their town. They become cautious when she starts nosing around the house seeking their father. When Matthew and Annie find her body in the yard, they confer and decide to bury her to prevent the inevitable attention from authorities an investigation into her murder would entail.
The whodunnit is wondering who, of the cast of adult around the kids, did the deed. Robert Barnard is a wonderful writer who is not afraid of leaving you with a few things to wonder about. This book is no longer in print, but is available as a used book and is well worth a little digging for an unusually good read.