A debt of honor has come due, and Nicholas Linnear—the Ninja—has vowed to pay it in full. Years ago he made a promise to his father: If a man named Mikio Okami ever sought his help, he would respond without question, no matter the cost. Now the time has come to fulfill his pledge…and meet his destiny. Mikio Okami is the Kaisho—the boss of the bosses of the Yakuza, the Japanese underworld. In his Venice headquarters, he realizes that he has been marked for death. But the identity of the assassin, and the inexorable compulsion that drives him, are shrouded in mysticism and madness. Honor-bound to protect Okami, Linnear is prepared to make the ultimate sacrifice: a descent into a chasm of knowledge so potent, of dangers so unfathomable, that even if he survives he will emerge changed forever.