America twenties. The economy is booming after the First World War, a growing number of rich people, but it is growing and the gap between rich and poor. Otherworldly forces are in the darkness of human souls,and increasingly demons appear in our world. But the charge is Magdala Order - a special institution of the Catholic Church, designed to hunt down and destroy the evil - and two exorcists: 16-year-old nun Rosette Christopher Chrono daemon usually resides in the body of 12-year-old boy. Companions bound unusual contract,according to which the Chrono is able to receive former appearance and use their paranormal forces exactly as much as the Rosetta shortened life. Duet brightest heroes destined not only to destroy the evil, but keep the personal accounts of the insidious demon Aion, who stole the Rosetta brother, Joshua;which in the past had a lot of common affairs with dark Crono and who intends to do with the Earth irreparable!