THE WRONG MOTHER by Sophie Hannah

I read in the October Marie Claire about The Wrong Mother, by Sophie Hannah. It's a genre I don't ever read – crime fiction – but it looked good to me. From Amazon:

Hannah

Sally Thorning is watching the news with her husband when she hears an unexpected name-Mark Bretherick. It's a name she shouldn't know, but last year Sally treated herself to a secret vacation-away from her hectic family life-and met a man. After their brief affair, the two planned to never meet again. But now, Mark's wife and daughter are dead-and the safety of Sally's own family is in doubt. Sophie Hannah established herself as a new master of psychological suspense with her previous novel, Little Face. Now with accomplished prose and a plot guaranteed to keep readers guessing, The Wrong Mother is Hannah's most captivating work yet.

The Wrong Mother doesn't come out until Tuesday, so there aren't many reviews out there yet. BookPage wrote about it in its October Whodunit? column (scroll to bottom), but I couldn't find much more about it. Sherri on Goodreads said, "Good read that kept me guessing and trying to figure out who did what to whom almost to the end', while Pam on Goodreads said it was confusing and went downhill after the first 40 pages.

Please weigh in when and if you've read it!