Author:  Sands, Kevin 
Interest age: from c 10 years
Published on 3 September 2015 by Penguin Random House Children's UK (Puffin) in the United Kingdom as part of 'The Blackthorn Series' series.

Paperback | 320 pages
198 x 193 x 20 | 228g
Follow the clues. Crack the code. Stay alive.
Potions, puzzles and the occasional explosion are all in a day's work for young apothecary Christopher Rowe. Murder is another matter.
It's a dangerous time to be the apprentice of Benedict Blackthorn. A wave of mysterious murders has sent shockwaves through London, and soon Christopher finds himself on the run. His only allies are his best friend, Tom, courageous Molly, and a loyal feathered friend, Bridget. His only clues are a coded message about his master's most dangerous project, and a cryptic warning - 'Tell no one!'The race is on for Christopher: crack the code and uncover its secret, or become the next victim . . .
A brilliant, fast-paced adventure perfect for fans of Percy Jackson.