GUILTY BY DEFINITION

A series of pseudonymous letters and postcards provokes a lexicographer to revisit the disappearance of her sister from their Oxford home 13 years ago.

The first missive, signed “Chorus,” is so cryptic, fantastical, and larded with Shakespearean quotations that Martha Thornhill, senior editor of the Clarendon English Dictionary, is certain it must contain a coded message, and with the help of Alex Monroe and Safiya Idowu, two members of her team, she deciphers it. Though its import still remains obscure, Martha suspects it’s communicating something about her elder sister, Charlotte, a Somerville College student who vanished while juggling work on her dissertation and her own stint on the CED. Martha, who returned not long ago from a bittersweet job experience in Berlin, gets surprising encouragement from DS Oliver Caldwell at St. Aldates Police Station, but neither of them knows quite what to do next. Luckily, they don’t have to decide, for Chorus unleashes a perfect torrent of postcards with obliquely threatening quotations and letters with a series of increasingly challenging ciphers to Martha and the rest of her team, along with consulting Shakespearean Jonathan Overton and Gemma Waldegrave, his agent and Martha’s godmother. Their professional and personal relationships are well and truly tangled, but they’re all upstaged by debut novelist Dent’s impassioned love of words. As Chorus, once unmasked, puts it, “We’ve all lost ourselves in words. They are our oasis and our downfall.”

Don’t worry if you can’t solve even the simplest cipher. There are pleasures here for anyone who revels in the joy of text.