Cornwall, 1940.

In the hushed hours of the night a woman is taken by the sea.

Was it a tragic accident? Or should the residents of Penhallow have been more careful about whom they invited in?

In the midst of war three women arrive seeking safety at Penhallow Hall.

Each is looking to escape her past.

But one of them is not there by choice.

As the threat of invasion mounts and the nightly blackouts feel longer and longer, tensions between the close-knit residents rise until dark secrets start to surface.

And no one can predict what their neighbour is capable of . . .

In a house full of strangers, who do you trust?