In the latter part of the century, if customers wanted to get hold of pornographic prints or even stereoscopic slides (giving the illusion of depth to indecent images), they usually had to have a discreet word with the bookseller. Even then, they were likely to have been treated with suspicion. In 1880, a police inspector went undercover in search of a family-run mail-order enterprise that was corrupting Eton pupils by sending them indecent images unsolicited in envelopes marked "art studies", in the hope that they would order more. The trail led straight to a Holywell Street bookshop. The officer found that risqué photographs could be purchased easily enough but to get his hands on some "choice specimens", as he puts it in his Stories from Scotland Yard (1890), the police officer had first to earn the keeper’s trust before being led upstairs into "a dirty little place, which was part bed-room, part workshop . . . as filthy a hole as I have ever been into". Here, he purchased some expensive hardcore pornography (for two guineas) — and left a shilling for the “little wretched piece of forlorn humanity” that was the shopkeeper’s baby. The pornographer’s suspicious wife followed him to the train station. The next day, the shop was raided, five thousand indecent photographs seized, and the man arrested. He was given two years’ imprisonment and the inspector rejoices in ending his “revolting trade”.