Abi Holland considers herself lucky.

She's happily married, and her oldest daughter, Eva, is all set for a place at a top university.

She just can't help but worry about Beth.

So when foreign exchange student Corinne comes to stay, it's a relief her lonely younger daughter finally has someone to talk to.

It's only when Beth starts to misbehave, that Abi begins to wonder how much they really know about their guest.

Because the Holland family have lots of secrets, and Corinne is quietly listening to them all.

And once they come out, there's no going back…