Turn down Slade Alley - narrow, dank and easy to miss, even when you're looking for it. Find the small black iron door set into the right-hand wall. No handle, no keyhole, but at your touch it swings open. Enter the sunlit garden of an old house that doesn't quite make sense; too grand for the shabby neighbourhood, too large for the space it occupies.

A stranger greets you and invites you inside. At first, you won't want to leave. Later, you'll find that you can't.

This unnerving, taut and intricately woven tale by one of our most original and bewitching writers begins in 1979 and comes to its turbulent conclusion around Hallowe'en, 2015. Because every nine years, on the last Saturday of October, a 'guest' is summoned to Slade House. But why has that person been chosen, by whom and for what purpose? The answers lie waiting in the long attic, at the top of the stairs . . .