The Maze Runner by James Dashner

Another dystopian page-turner!  Thomas finds himself delivered via freight elevator to an enclosed compound with no memory except for his name.  He is greeted by other teenage boys to a large area surrounded by stone wall they call the Glade.  Nobody knows why they are there, and for two years they have been searching for a way out.  Doors to the outside open each morning leading to a maze that changes each day.  By nightfall the massive doors shut which keeps the horrible half-slug, half-machine monsters from entering their Glade.  There's much action, much mystery, and a sequel called The Scorch Trials.