Caprona is a city-state in the Italy of Chrestomanci's world (World Twelve A), which never united as a
nation-state. The houses of Casa Montana and Casa Petrocchi, both renowned for being powerful magician families, have been feuding with each other for generations. The city has begun to lose its "
virtue", and the states of
Florence,
Siena, and
Pisa intend to take advantage of this by uniting to conquer Caprona. The only way to save the city is if the true words to the
Angel of Caprona, both a hymn and a powerful spell, can be found and read aloud. The story is told through the eyes of the young Tonino Montana and his brother Paolo. They are both members of Casa Montana, one of two spell-houses in Caprona, the other being Casa Petrocchi. The two spell-houses are deadly rivals; the two families are both convinced that the decline of Caprona is all the fault of the other spell-house, and refuse to work together under any circumstances. Tonino is, unknown to himself or the rest of Casa Montana, a talented enchanter, but he is unaware of his ability, and prefers to spend his time reading. Paolo is more outgoing and friendly, and does better at school. When representatives of both houses are called to the Duke of Caprona's palace, they both go. Whilst there, they meet members of the Petrocchi family for the first time, and they also encounter the Duchess, a powerful woman who appears to be the true ruler of Caprona. During the book, Tonino is kidnapped and finds himself held hostage with Angelica Petrocci and whilst the two houses blame each other, Tonino and Angelica have to put their differences aside to escape. Meanwhile, Paolo teams with Renata Petrocci in order to save their lost siblings. ==Characters==