'The twist is perfection. I think it's just about the cleverest thing I've ever read' Gillian McAllister

You think it will never happen to you: the ring of the bell, the policeman on the doorstep. What he says traps you in a nightmare that starts with the words, 'I'm afraid…'

Sally Lambert is also afraid, and desperate enough to consider the unthinkable. Is it really, definitely, impossible to escape from this horror? Maybe not. There's always something you can do, right?

Of course, no one would ever do this particular something - except the Lamberts, who might have to.

No one has ever gone this far. Until Sally decides that the Lamberts will…