I've read a lot of Torday's books and found them to be excellent. A genius storyteller who was take from us way too soon.
Here's the synopsis:
Elizabeth has been married to Michael for ten years. She has adjusted to a fairly monotonous routine with her wealthy, decent but boring husband. Part of this routine involves occasional visits to Beinn Caorrun, the dank and gloomy house in a Scottish glen that Michael inherited.

But then Michael begins to change.

It starts when he thinks he sees, in a picture, the figure of a girl on a landing. As he changes, life becomes so much more fun and Elizabeth sees glimpses of a man she can fall in love with at last.

But who - or what - is changing Michael?

Popping into the Read it, swap it, leave it bookring. Hopefully to find another reader who enjoyed it as much as I did.

Taking from the BookBox.