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?

The answer is in the cells where a pair of kidnapped humans and a pair of aliens are incarcerated. Destined to become the subjects of a brutal experiment. The Rani forges an unholy alliance with the four "guinea-pigs" in a perilous attempt to escape the nightmare of the planet...