This is the third book in the Matched trilogy. The Rising has come and to win followers, they released a deadly flu virus into the Society's water. They have a vaccine and everyone who gets it is healed, but soon the virus mutates and they do not have a vaccine against the mutated form. It becomes a race against time to find a cure and it becomes even more urgent when Ky falls ill. But there are people working against the Rising to make sure as many people as possible die. Will a cure be found in time to save Ky?