The Placer — John Greenwood

A Placer is someone who stops bad things from happening before they do. Martin Howell is one of them. His latest assignment sends him to a middle school in South Florida where an anonymous emailer has been threatening a massive school shooting. Martin goes in undercover as a teacher to try and stop it before it's too late, but will it be enough. If you are a fan of Robert Crais or Lee Child this book is for you.