Every typesetter has a horror story. Imagine: you’ve spent hours – days – laying out text, proofing it, waiting for approval. You’ve sent the thing to the printer and waited some more for finished copies to arrive. You’ve taken a box cutter to cardboard and pulled out your handiwork, beautifully realised in gleaming ink and paper, only to see something that will haunt you for years to come. A typo. I still have nightmares about the time I misspelled a famous actress’s name in headline-sized letters over a decade ago. According to Rebecca Lee, there’s a patron demon (think patron saint but less benevolent) for me to blame.

Titivillus started his career as a kind of supernatural snitch working for the Devil, telling on priests and parishioners whose minds wandered and who made mistakes as a result. Soon, Lee explains, he was not just informing on erring church types but causing them to blunder. Scribes who smudged or misspelled words blamed Titivillus. As manuscripts gave way to printed books, Titivillus learned new tricks: spiriting away entire lines of text, inverting letters, damaging type. From the early days of printing, Lee writes, ‘error was celebrated as an integral part of a book’s life’. Enter the errata lists, correction slips and replacement pages. These came in handy for the 1611 King James Bible, in which you will find ‘Judas’ when ‘Jesus’ was meant. Winston Churchill demanded a tipped-in slip for the first edition of The Gathering Storm, in which it was too late to correct his description of the French Army as ‘the poop of the French nation’.

Such slip-ups matter because they chip away at the trust between reader and writer. There is, Lee argues, an ‘implicit contract’ made by a book: ‘the writer vouches that what is written under their name reflects their honest thoughts’ and the reader agrees to believe them. This contract is broken