Caz has been trapped in a department store for 9 years since an asteroid crashed to Earth and caused the world outside to be icy cold and toxic. Marky the leader rations food and rules with an iron fist and when supplies run low, he demands a sacrifice - a person exiled into the icy wilderness. Caz and Will argue with Marky and end up as the sacrifice. Caz has peaked out a window and seen movement - she believes there are others alive outside the store but can she and Will find them. And, if this is so, why haven't any of the previous sacrifices come back to the store? ( )