When Elspeth arrives on a remote Scottish island to become nanny to a young child, she hopes to bond with her. Until she learns that, for reasons no one will explain, Mary has not spoken for months.

And the girl's silence is not the only mystery. Hypnotic lullabies drift down empty corridors. Strange dolls appear in abandoned rooms. And as the nights draw in, darker questions arise . . .

What happened to Mary's late twin, William? Why did their previous nanny disappear so suddenly? And is the whistling Elspeth hears at night just the storm outside? Or is somebody coming for her . . . ?