This is the 5th episode of the Namek Saga in the original dubbed Dragon Ball Z series.
Recap
The episode begins with Bulma, Krillin and Gohan trying to retrieve the sixth Dragonball from an ice cave. Gohan and Krillin use energy waves to slowly melt the ice, so as not to keep the cave from collapsing. They get the dragonball but the cave collapses anyway. Zaacro mysteriously disappears. Krillin, Gohan, and Bulma ride a block of ice down the tunnel. Two shadowy figures make a boulder chase after them.
Meanwhile, on Earth, Goku continues his training, but becomes seriously injured again after crashing through a pyramid.
Back on Namek, Gohan and Krillin blast the ceiling to make stalactites fall to slow the boulder down, but instead it runs over them and becomes spiked. They and the boulder reach an exit and fall off a cliff, but Gohan and Krillin fly, holding Bulma between them. They head for the seventh Dragonball, but Krillin recognizes the area as the spot where they chased the dinosaur. The last Dragonball is inside a stone building, but just as Gohan goes to get it, invisible enemies attack him.
Goku is found by Chi-Chi and Master Roshi, who take him back to the hospital. While on Planet Frieza, Vegeta plans to leave for Namek, but runs into his rival, Frieza's henchman Cui. Cui tells Vegeta that Frieza is on Planet Namek, having heard Raditz's message about the Dragonballs. Vegeta grabs his scouter and heads off in his space pod toward Namek as quickly as he can.
Raiti and Zaacro appear and reveal that they are not Nameks, but pink, spiked, shapeshifting aliens. They reveal that they are not on Planet Namek and that they created the illusion of a Planet Namek, and all their quests were one illusion. The Dragonballs were nothing more than stones. When the illusion fades away, Gohan's attackers are revealed as man-eating monsters.
Trivia
- Why didn't Krillin and Gohan blast the boulder that was chasing them?