In Pandemic, only a few people know what caused Lilianna Snyder's sudden change from a model student to a withdrawn pessimist who worries about all kinds of disasters. When people begin coming down with a quick-spreading illness that doctors are unable to treat, Lil’s worst fears are realized. With her parents called away on business before the contagious outbreak, Lil’s town is hit by what soon becomes a widespread fatal illness.

With friends and neighbors dying around her, Lil must find a way to survive not only the outbreak and its real-life consequences, but also her own personal demons.