The Compound by S.A. Bodeen
This first novel by author Bodeen is a truly gripping thriller. Eli, 15 years old, and most of his family have been locked away for the last six years in a massive underground shelter built by his billionaire father. Life on the outside has been destroyed by a nuclear war that also claimed the lives of Eli's twin brother and grandmother who were unable to make it to the shelter in time. They have 9 years to go before the door to the shelter can be unlocked but they are running out of supplies and won't last much longer. But then Eli makes a shocking discovery that changes everything.