In Victorian London, the age of consent was just thirteen. Unwitting girls were regularly enticed, tricked and sold into prostitution. If not marked out for a gentleman in a city brothel, they were legally trafficked to Brussels, Paris and beyond.

All the while, the Establishment turned a blind eye. That is, until one policeman wrote an incendiary report. Disgraced for testifying against a violent colleague, Irish inspector Jeremiah Minahan was transferred to the backwater of Chelsea as punishment.

Here he met Mary Jeffries, a notorious trafficker and procuress who counted Cabinet members and royalty among her clientele. Within days of reporting Jeffries, Minahan was unceremoniously forced out of the Metropolitan Police. So he turned private detective, setting out to expose the peers and politicians more interested in shielding their own positions (and peccadilloes) than London's child prostitutes.