The gripping fourth book in the #1 New York Times bestselling Supernatural Investigations series that began with Amari and the Night Brothers! Perfect for fans of Tristan Strong Punches a Hole in the Sky, Percy Jackson and the Olympians, and Nevermoor.

Fourteen-year-old Amari used to be a Junior Agent at the Bureau of Supernatural Investigations, where she dealt with all kinds of weird and wonderful creatures. But ever since the war with the League of Magicians, Amari has stepped back from the Bureau to spend the school year as a normal kid. As she prepares to graduate eighth grade, she's faced with a decision: Return to the Bureau and join the elite new Junior Special Agent Program, or retire for good—which would mean safety, but also losing her memories of the supernatural world.

But soon she finds that she may not have a choice. A deadly new curse is threatening both the supernatural and mortal worlds as, beneath their skin, people are slowly becoming machines—and losing their very humanity. And it's somehow related to the First Magician.

Hundreds of cases have been cropping up, with no cure in sight. And when the curse hits someone close to Amari, it's up to her to get to the bottom of this deadly mystery—even if it means trusting an old enemy...

Read all of Amari's adventures:

1. Amari and the Night Brothers
2. Amari and the Great Game 
3. Amari and the Despicable Wonders
4. Amari and the Metalwork Menace