Off-cum-den (old Yorkshire dialect): off-comer; outsider; one who doesn't belong.

South Yorkshire, 1984.

From his garden shed, thirteen-year-old Chrissy-boy Foster is watching his world fall apart. His dad's in prison for a picket-line fight. His mum is on the edge of a nervous breakdown. Sadie - Chrissy-boy's sister - is kept locked in her room. 'She's poorly' is all he's ever told. But despite his sheltered upbringing, Chrissy-boy knows there's much more to her frightening condition.

When his dog runs away, Chrissy-boy teams up with two other school outsiders: Aasha, a Kashmiri girl newly moved onto the council estate; and Mickey, from the old traveller family that runs the local scrapyard. Their search pulls them into Black Carr, the sprawling primal forest that edges the council estates of Rother valley. Beneath those woods, something is waking - something ancient and evil, something that connects their families and their secrets, their guilt.
As the three friends journey deeper into the heart of the valley, they begin to uncover the horror that their parents and grandparents had tried to bury . . . but that the land itself refuses to forget.