Reunions

Goku and Gohan arrive at Kame House to reunite with Bulma, Krillin, and Master Roshi after five years apart. The friends marvel at Gohan's polite manners, his Saiyan tail, and the Four-Star Dragon Ball on his hat. Their light-hearted catching up takes a dark turn when Goku senses an overwhelming power headed straight for them.

Revelations and Ruin

The alien, Raditz, introduces himself as Goku's older brother and a Saiyan warrior. He knocks Krillin through the wall of Kame House with a flick of his tail. Master Roshi confirms the shocking truth: Grandpa Gohan once found baby Goku in a space pod, and a head injury erased his violent Saiyan instincts. Raditz explains that their homeworld, Planet Vegeta, was destroyed, leaving only four Saiyans alive. He demands Goku join him to conquer a distant planet. When Goku refuses, Raditz kidnaps Gohan and delivers an ultimatum: kill one hundred humans, or never see the boy again. A single knee strike sends Goku crashing to the ground, helpless to stop his brother from flying away with his son.

Raditz's arrival permanently redefines Goku's identity. He is not simply a gifted martial artist; he is a member of a warrior race sent to Earth as an infant with orders to destroy all life on the planet. The revelation that only four Saiyans remain, including two even stronger than Raditz, plants the seeds for the battles to come.

A Father's Failure

Goku's inability to protect Gohan despite being Earth's strongest fighter demonstrates how drastically outmatched he is. Raditz treats the entire group as beneath his notice, establishing the Saiyan threat as something beyond anything the Z Fighters have encountered before.

This episode rewrites the foundation of the entire Dragon Ball story. Goku's alien heritage, his original mission of destruction, and the existence of other Saiyan warriors transform a martial arts saga into an interstellar conflict. The kidnapping of Gohan forces Goku into the most desperate situation of his life, setting up the alliance and sacrifice that define the Raditz Saga.