Constantinople. For a thousand years, the city was the heart of the vast Byzantine empire. Beloved of Greeks. Coveted by Turks. 1453. The empire has shrunk to what lies within its no-longer magnificent walls. Yet for one man, Constantinople is the stepping stone to destiny. Mehmet 11, just twenty when he is anointed Sultan, brings an army of one hundred thousand, outnumbering the defenders ten to one, and the most deadly threat the city has ever faced - the largest cannon in the world. But a city is more than stone, its fate inseparable from its citizens. Like Gregoras, mercenary and exile, returning to the hated place he once loved. Theon, his twin - and betrayer. Sofia, loved by two brothers, forced to choose between them. And Leilah, mystic and assassin, seeking her own destiny in the flames...