Deep in the Cambridgeshire fens, Laura is living alone with her 12-year-old daughter Beth, in the old tollhouse known as Ninepins. She's in the habit of renting out the pumphouse, once a fen drainage station, to students, but this year she's been persuaded to take in 17-year-old Willow, a care-leaver with a dubious past, on the recommendation of her social worker, Vince. Is Willow dangerous or just vulnerable? It's possible she was once guilty of...