Hiro-Kala is a boy with humble origins and a deadly secret. A former slave, he is the son of the Incredible Hulk and the Sakaarian queen Caiera, a child possessed of tremendous power - and an insatiable wrath! When his home world is destroyed by Galactus, Hiro-Kala swears vengeance on the Devourer of Worlds. And with his natural affinity for the deadly Old Power, inherited from his mother, he has the muscle to make good on his threats. Like all of the Hulk bloodline, he has a drive to conquer. Adrift in space with the remaining refugees of his destroyed home, the boy sets his sights on the strange planet Gaiusar, a world with deep connections to the Old Power. If he can subdue the natives and seize the rich Old Power for himself, he'll emerge as a force as powerful as any in the known universe. But when Galactus arrives, eager to sate his devastating hunger, Hiro-Kala finds himself in a fight for his life, with the fate of Gaiusar hanging in the balance!