Scientists on the Great Island have edited humankind to have no other emotions besides happiness--with no possibility of mutations which might allow them to return to normal. Born with all his emotions, David Stevenson lives in a disappointing world with few others like him. In school, he meets someone like himself named Clay, and when he goes with his mother to the grocery store, David sees how society has collapsed. When the leaders choose to start searching for the few people with mutations, David and Clay's friendship ends. Years later, after struggling to find companionship, David finds more people like himself when he seeks out a rumored hidden cave, but the scientists are close behind.