The unconventional follow-up to 2017's The Young Pope begins with Lenny Belardo, aka Pope Pius XIII, in a coma after a heart attack as the Holy See searches for his replacement. British intellectual Sir John Brannox is elected to the papal throne, assuming the name John Paul III. He soon finds that his predecessor's shadow looms large: The fiercely devoted cult of Pius XIII believes their pope will return, and their conviction proves hard to shake.