Untitled Mystery: A New Cain's Jawbone Puzzle

The official sequel to Cain’s Jawbone, the global publishing phenomenon.

In 2019, Unbound re-published a 1934 murder mystery in which the pages had been printed out of order. Re-assembling in them right order turned out to be a literary puzzle of fiendish difficulty (as you might expect given the author was Edward Powys Mathers better known as the infamous ‘Torquemada’, the man who set the cryptic crosswords for the Observer).

Only two people solved the puzzle back in the 1930s and the first person to solve it since then was the British writer and puzzler, John Finnemore. Aided by word of mouth and TikTok, Cain’s Jawbone has sold half a million copies, been translated into 12 languages and become a bestseller in every language it’s appeared in.

Now, John Finnemore has returned with his own challenge: the first murder mystery ever to be presented in the form of a box of picture postcards. Everything about John's sequel is a mystery – including the title (which will be revealed to people who pledge during the crowdfunding campaign).

The new mystery

At the end of last year, a certain person was found stabbed to death in the study of a complete stranger. The room was securely locked from the inside, but no weapon – or murderer – was ever found. Not only that, but the police investigation discovered no credible suspects, nor even a likely motive – the victim had no living family, no known enemies, and left all their money to charity. Why should anyone have murdered them… and how could they have done so?

Many miles away, their murderer keeps, safely locked in a drawer, a box of 100 picture postcards. These, if arranged in the correct order and properly understood, would explain not only that murder, but nine others that took place in the same year…

The solution

Solvers must identify the killer, victim and method in all ten murders, as well as the address at which the final victim was found. To do this, not only must they correctly order and understand the story told in words on the back of the postcards, in the manner of Cain’s Jawbone, but they will also need to solve the the visual puzzles presented by the picture sides, the first of which is usually: ‘How on earth can this be a puzzle?’

John says that his hope is to create something that is as difficult to solve today as Cain’s Jawbone was in 1934. By which he means, very difficult indeed… but with perhaps less need to research the licensing laws of different districts of London in the 1930s.

The competition

As with the original Cain’s Jawbone, Unbound will be running an online competition with a prize of £1,000 for the first person to solve all the elements of the Untitled Mystery puzzle. The competition will run for one year from the date of publication.

Note: The postcards shown are not solvable with the information given. Don’t torture yourself…yet.