Life in the Underground United States really freakin' sucks. No freedom, no sunlight, and the whole place smells like armpit. That's what life has been like for Sam and his little sister Ella for the past eight years, ever since the Draft took their parents. So pretty much hell. But at least they had each other. ​Until they didn't. As if Underground life couldn't get any worse, Ella mysteriously goes missing without a trace. Sam must now embark on a dangerous journey through the unknowns of the Underground to find her. But will he find her before it's too late? Will a brother's love be enough to save her?