Wake Up Missing — Kate Messner

Meet Quentin, a middle school football star from Chicago...
Sarah, an Upstate New York girls' hockey team stand-out...
Ben, a horse lover from the Pacific Northwest...
And Cat, an artistic bird watcher from California.

The four have nothing in common except for the head injuries that land them in an elite brain-science center in the Florida Everglades. It's known as the best in the world, but as days pass, the kids begin to suspect that they are subjects in an experiment that goes far beyond treating concussions....and threatens their very identities. They'll have to overcome their injuries - and their differences - to escape, or risk losing themselves forever.