The Empress of Timbra

Fourteen-year-old Taver didn't know he was a nobleman's bastard until his real father died. Eleven-year-old Elaku has always known she was the bastard daughter of the same nobleman - and the Empress's Witch. When the two siblings meet in the Empress of Timbra's palace, neither is aware that treachery and war threaten their home - and that they must rely on their magic, their wits, and each other to have any chance of victory.