The Rani is a prisoner. Of the Tetraps. Those hideous rodent-like vampires over which she once ruled. No longer. The devious Urak, her erstwhile disciple, has turned the tables. The Rani is put on trial. And condemned to death. A sentence to be commuted if she exercises her unique scientific prowess to solve a problem threatening to depopulate Tetrapyriabus. Famine. Shortage of food. What food? Blood. Whose blood?