The turn of the key

"When [nanny] Rowan Caine arrives at Heatherbrae House, she is smitten--by the luxurious 'smart' home fitted out with all modern conveniences, by the beautiful Scottish Highlands, and by this picture-perfect family. What she doesn't know is that she's stepping into a nightmare--one that will end with a child dead and herself in prison awaiting trial for murder"--Provided by publisher.