Seventeen-year-old Jay Harris lives in a world struck down by a deadly virus. His parents are dead, along with half the planet. When Jay's sister Maia falls ill, he must find a cure before he loses her, too. But unbeknownst to Maia, Jay is also sick...and he's running out of time to save them both.
When Jay's friends tell him there might be a cure for him in France, he must decide whether to pursue it. The journey will be difficult and dangerous, especially in his weakened state, but with little time left - for himself and for Maia - it soon becomes clear there's no other choice.
Jay leaves the relative comfort of London to search for help, knowing he may never find it. Along the way, he experiences the effects of disaster on the bonds of friendship and fluctuating notions of family. These teens, decimated by a dangerous plague, face stark choices in their search for help, not knowing if their efforts will end in loss and pain. Will Jay and Maia find a cure before the virus takes them?