An unidentified virus wipes out most of the Earth's population and Leon, his mother, and younger sister Grace, who just moved to London from New York, must run for their lives.

THEY THOUGHT IT WAS DEAD. THEY WERE WRONG. Two years ago, a virus hit London, killing thousands of people and driving the rest into hiding. But Leon has somehow survived, making it through two harsh winters. Now he's living on the fragile hope that the freezing snow and ice of the English climate wiped out the virus for good. Word even reaches Leon of a rescue boat on its way. But all is not as safe as it seems. The virus has been busy...