From New York Times bestselling author Neal Shusterman comes a young adult thriller about a world where happiness is contagious but the risks of catching it may be just as dangerous as the cure. A deadly and unprecedented virus is spreading. But those who survive it experience long-term effects no one has ever seen before: utter contentment. Soon after infection, people find the stress, depression, greed, and other negative feelings that used to weigh them down are gone.

More and more people begin to revel in the mass unburdening. But not everyone. People in power--who depend on malcontents and prey on the insecure to sell their products, and convince others they need more, new, faster, better everything--know this new state of being is bad for business. Surely, without anger or jealousy as motivators, productivity will grind to a halt and the world will be thrown into chaos. Campaigns start up to convince people that being eternally happy is dangerous. The race to find a vaccine begins. Meanwhile, a growing movement of Recoverees plan ways to spread the virus as fast as they can, in the name of saving the world.

It's nearly impossible to determine the truth when everyone with a platform is pushing their agenda. Three teens from very different backgrounds who've had their lives upended in very different ways find themselves at the center of a power play that could change humanity forever.