HarperCollins Children’s Books has acquired Iona Rangeley‘s brand-new middle-grade spy series, beginning with the “thrilling” Cecily Sawyer: How to Be a Spy.

In an announcement in The Bookseller, which subscribers can read in full here, editorial director Tom Bonnick said:

“Iona is a fast-rising star of children’s fiction and we’re delighted to  be building on the success, widespread praise and genuine reader love for Einstein the Penguin with this fantastic, funny and exhilarating new middle-grade series, which stars a formidable young heroine, a cast of hilarious spies, and several most unusual mice.”

Cecily Sawyer has spent the evening in the attic, training her pet mouse, Mrs Maple-Syrup – an unusually intelligent mouse, in Cecily’s opinion – when her parents disappear. Luckily, Cecily is more than ready to investigate such a thing. She has wanted to be a spy her whole life, and has all the spy handbooks, manuals and code-cracking kits a girl could need.

But soon, Cecily discovers several very strange things in her city. She’s not the only spy out there – far from it, in fact. And Mrs Maple-Syrup is not the only unusually intelligent mouse…

Cecily Sawyer: How to Be a Spy will be released in the UK in June 2025.

Follow Iona on Twitter @IonaRangeley.