The Secret Zoo: Traps and Specters by Bryan Chick

Description

"He's coming for us," Mr. Darby said at last. "For the first time since we drove him out of the Secret Zoo—the Shadowist is coming."

Noah, his sister Megan, and their best friends, Ella and Richie, have spent more than a year protecting the Secret Zoo. But now they're facing a greater danger than ever before. DeGraff has been spotted on the streets. He's moving closer and closer to the Secret Zoo. Old friends and new allies must work together if they want to stop the Shadowist. But can Noah and the Scouts trust everyone who claims to be on their side?