Sixteen years have passed since "Black Blood." The bison clan has gradually healed most of the wounds inflicted by the incursion of dwarf-diatrites and by the awakening—and then the death—of one of the four pre-lords of Külkas. The children born after those events have grown up, and among them is Tashi, the son of the legendary Tashi the Bowman—the victor over the mangas warlock. It seemed that the old troubles had slipped into the past, but a much greater misfortune has taken their place. Suddenly several neighboring clans fight among themselves; attacks on people of the bison also follow. Soon it becomes clear that all this is the work of the menks—strangers unknown to people before—creatures capable of casting illusions by posing as others and of bending wills to their own. Only by straining every strength can the sorcerers hold the menks’ attacks back for a time—but it quickly becomes obvious that this isn’t enough: the jade knife must be found and returned—the one with which Unika, Tashi’s wife, once killed Külkas. And if even that won’t suffice, help must be sought from Bayun, an ancient magician whose cave is where great magicians of former times from many different peoples spend their lives. And who else, if not Unika with her son, can carry out this task, fully changing the World.