The second thrilling, mysterious and very, very funny CECILY SAWYER mystery, from the award-winning author of EINSTEIN THE PENGUIN.​

Cecily Sawyer is surrounded by spies. They’re everywhere – on the streets, in her home, at her school – and after intercepting a highly suspicious message intended for her parents (also spies), Cecily, along with her highly-intelligent pet mouse, Mrs Maple Syrup, decides to investigate.​

And the more that Cecily digs, the further the mystery deepens … forcing her to question who – if anyone – she can really trust.

Hugely gripping, incredibly funny, and highly original, How to Crack a Code is an unputdownable mystery – perfect for fans of Robin Stevens and Katherine Woodfine.

Also available in the series:

Cecily Sawyer: How to be a Spy

Praise for Cecily Sawyer: How to be a Spy:

'With so many undercover agents vying for attention, the choice can seem daunting – but Cecily Sawyer: How to Be a Spy, a delightful new adventure by Iona Rangeley, shows the detective formula working at its best … Rangeley is a witty, beguiling writer – and what follows is a neatly plotted adventure, in which each clue forms part of a puzzle which the reader can piece together as the narrative rips along.' – The Telegraph

'Whip smart, absolutely hilarious and full of charm.' – Laura Noakes, author of Cosima Unfortunate Steals a Star

'A fabulous book' – Zohra Nabi, author of The Kingdom over the Sea

'A charming and elegant corrective to the notion that 10 year-old girls and mice have no role to play in espionage.' – Luke Jennings, author of Killing Eve

'I firmly recommend this book. A very good start for those who want to join the profession or who just want a good read.' – Sir John Scarlett, former Chief of MI6 (really)