The most feared world in the galaxy: The Well of Furies. From this planet, the godlike Ulltrians waged war on all life among the stars.
Long thought dead, the Ulltrians have returned. All the inhabited worlds–including Earth–are now in danger. Only one military force can stop the Ulltrians: the Predator Corp.
Amir Tarkos is one of the only humans in the Predator Corp. With his partner Bria, a bear-like carnivore, Tarkos is given a dangerous and difficult mission. Tarkos and Bria must locate the World Hammer, a pair of co-orbiting sunless planets that are the last refuge of the Ulltrians. But to find the World Hammer, they first must brave the dangers of the Ulltrian homeworld.
To save Galactic civilization, Tarkos and Bria will have to work with a team of strange aliens and artificial intelligences, explore the perilous ruins of an ancient world, dare the depths of an ocean that engulfs a dark planet, and fight a fierce battle in the ice rings of a gas giant.