THE INSTANT SUNDAY TIMES BESTSELLER!
'ONE OF THE FINEST MYSTERIES I HAVE EVER READ' 
Rob Rinder, Sunday Times bestselling author of The Trial
'A TANTALISING MYSTERY FOR WORD SLEUTHS AND CRIME FANS ALIKE'
Janice Hallett, Sunday Times bestselling author of The Appeal
**AVAILABLE TO PRE-ORDER NOW**
A coded letter. A missing woman. A truth waiting to be found.  
When an anonymous letter is delivered to the Clarendon English Dictionary office, it becomes rapidly clear that this is not the usual word-related enquiry. Instead, the letter hints at sinister events linked to a particular year.
For editor Martha Thornhill, the date can mean only one thing: the summer her brilliant older sister Charlie went missing. Ten years on, Martha and her family are no closer to unravelling the mystery of Charlie's disappearance - until now.
As more letters arrive, Martha and her team follow the linguistic clues to a troubling truth. It seems Charlie was keeping a powerful secret, and that someone is desperate to keep it well and truly buried.
Guilty by Definition is a love letter not only to language but to the city of Oxford, wrapped within an intriguing mystery of a missing woman and considering the emotional aftershocks of her disappearance on those left behind.
Guilty by Definition was a Sunday Times bestseller August 2024




![Cassidy, Marie BARGAIN CRIME FICTION Marie Cassidy: Body of Truth [2023] paperback](http://chaptersbookstore.com/cdn/shop/files/cassidy-marie-marie-cassidy-body-of-truth-2023-paperback-57205093368147_{width}x.jpg?v=1726975397)
![Coffey, Edel BARGAIN CRIME FICTION Edel Coffey: Breaking Point: The most gripping debut of the year - you won't be able to look away [2022] paperback](http://chaptersbookstore.com/cdn/shop/files/coffey-edel-edel-coffey-breaking-point-the-most-gripping-debut-of-the-year-you-won-t-be-able-to-look-away-2022-paperback-57289708896595_{width}x.jpg?v=1727455988)
![Mackintosh, Clare BARGAIN CRIME FICTION Clare Mackintosh: Hostage: The gripping new Sunday Times bestselling thriller [2021] paperback](http://chaptersbookstore.com/cdn/shop/files/mackintosh-clare-clare-mackintosh-hostage-the-gripping-new-sunday-times-bestselling-thriller-2021-paperback-57666877915475_{width}x.jpg?v=1727579469)
![Spain, Jo BARGAIN CRIME FICTION Jo Spain: The Last to Disappear: a chilling and heart-pounding thriller perfect for winter nights [2022] paperback](http://chaptersbookstore.com/cdn/shop/files/spain-jo-jo-spain-the-last-to-disappear-a-chilling-and-heart-pounding-thriller-perfect-for-winter-nights-2022-paperback-57846056386899_{width}x.jpg?v=1742662444)