Blood Trillium — Julian May

Twelve years after the princesses Haramis, Kadiya, and Anigel wielded the three-part Sceptre of Power to vanquish the sorcerer Orogastus, the Archimage Haramis is visited by a fugitive who brings dire news. A sorcerer has escaped from the Kimilon, remote Land of Fire and Ice, to establish himself through force of magic as Portolanus, Master of Tuzamen. Haramis's talisman cannot--or will not--tell her whether Portolanus is the long-banished Orogastus, but it brings ominous intelligence: The sorcerer has brought from his exile a magical object that can unbond the three talismans of the Sceptre, transferring their powers from the sisters to Portolanus himself. Even more fearsome, Haramis's talisman reveals a grave threat to the unity of the sisters and the future of Ruwenda...for the sacred Black Trillium contained within the amulet worn by each sister has changed, its petals stained the color of blood.