A boy afraid of heights must foil a terrorist group’s evil plot—and save their hostage, his dad—from inside their fortress in the sky in this middle grade action-adventure thriller perfect for fans of Alex Rider and City Spies.

It’s Micah’s thirteenth birthday, and he’s agreed to meet his dad, the famous architect and developer Bradley Broovert, at the top of his latest triumph. The Initium Tower is billed as the tallest building in the Western Hemisphere, right here in their hometown Atlanta, Georgia. Why start his birthday there? Micah is deathly afraid of heights but trying to prove to himself—and to his dad—that he can conquer the fear and not be controlled by it.

But when Micah gets to the roof, he sees his dad ascend into the clouds on a platform, then accidentally triggers the same mechanism and finds himself living his worst nightmare: moving ever higher and farther away from solid ground with no way to stop. Luckily, he’s saved just in time by a boy his age who pulls him into an air fortress hidden behind hi-tech cloaking.

The boy, Sigmund, is the stepson of the Blacksmith—the leader of a fringe group called the Forge Movement. The Blacksmith has kidnapped Micah’s dad for his knowledge of the Initium Tower, which will be used to project a disrupting signal and wipe out all electronic devices as part of phase one in a plan to take over the city—starting in one hour.

With no way to call for help, it’s up to Micah and Sigmund to foil the Blacksmith’s plan, all while hovering above the tallest skyscraper on this side of the world. If Micah wants to save his dad before it’s too late, he’ll have to remember not to look down…