There’s an old lady called Maud. She has trouble with her memory. You quickly realise the trouble is very bad. For instance, before she goes to the shop she writes a list, and then forgets it, and buys some tinned peaches, and you feel for her because she’s only just bought tinned peaches. Emma Healey, who won the Costa first novel prize for this, gets inside Maud’s mind superbly well. You begin to feel what it might be like to have a visitor, and forget the visitor is in your house, and then be surprised when she comes into the room. And now Maud thinks her friend Elizabeth is missing, and, compellingly, she is determined to investigate.