The Shadow Cipher

In a reimagined New York City, a pair of twins and their friend live in a building tied to a famous old mystery. When a developer threatens to tear down their home, they discover that the city’s long-unsolved cipher may be real after all.

To save the building, the kids follow clues left behind by brilliant inventors from the past. Their search sends them across an altered city full of strange machines, hidden places, and layered history, while they try to outpace people who want the treasure for themselves.

As the mystery deepens, the children uncover more than a simple puzzle. The search tests their friendship, courage, and understanding of their city, and the book ends in a way that points toward the next stage of the larger mystery.