More than a decade ago, a horrific sex-trafficking scandal rocked Britain. Starting in the late 1990s, thousands of mostly white girls in the post-industrial north of England, many from struggling families, were groomed by networks of mostly Pakistani men, who often professed to be their boyfriends before trapping them in a hell of repeated rape and prostitution. Several girls were murdered.

The mass abuse went on for years as those who tried to sound the alarm – including Sara Rowbotham, a health worker in the town of Rochdale; a Manchester detective constable, Maggie Oliver; and a member of Parliament from West Yorkshire, Ann Cryer – were largely ignored.