A riveting story of adventure, danger and friendship for readers 11+, perfect for fans of Alex Rider and CHERUB.

What would you risk for a friend you''ve never met . . . ?

In 1960s Berlin the Wall is everywhere. It cuts through streets, parks, even houses. Teenagers Harry and Jakob live either side of the divide.

In West Berlin, American Harry witnesses the brutal shooting of a boy trying to escape over the Wall into the West, and decides to emulate his comic book heroes and help those in the East however he can.

On the other side in East Berlin, Jakob is the adopted son of a high up Stasi officer, feeling suffocated by the rules of a strictly regimented society and desperate to find his real family.

When Jakob finds a message that Harry has sent over the Wall, he grasps the opportunity. The boys begin a secret friendship, evading the authorities using lemon juice as invisible ink to share hidden messages.

They soon realise that a bold plot to carve a tunnel under the wall is the only way out for Jakob – and it''s time to put their friendship to the test. Just how much are they prepared to risk for each other – and for freedom?

''A real page turner which will keep you reading long after you should have turned out the light!'' Independent Book Reviews – Fiona Sharp

''It has everything a school Library Manager could possibly hope for in a book to recommend to their students. It gives the reader historical knowledge. It is an adventure. It is thrilling. The pacing is perfect. There is no bad language'' Dudley School Librarian