"You are a criminal, Gemm 16884--aggressive, hostile, nonconforming. We have noted tendencies toward diversity in your gait, in your dreams, and most especially in your repeated persistence in"--the Elder cleared his throat--"making music."

Branded a deviant--and therefore a threat--to the utopian society of Conformity, Harmony, and Tranquility that exists in the year 2407, Gemm 16884 is given the choice between being recycled or undergoing a painful and mysterious cure. Gemm chooses the cure, and suddenly finds himself living the life of Johannes, a 16-year-old Jewish musician in Strasbourg, Germany, in 1348, at the onset of the Black Death. As the pestilence spreads, the townspeople begin to accuse the Jews of causing the disease. Surrounded by hatred and horror, Johannes struggles to hold on to his family and faith as well as his belief in the basic goodness of human beings. But can he return to the future and become Gemm again after having known such emotions as pain. . .and love?

(From Goodreads)