The barrier is destroyed by Bulma, who also came with the antidote for the Destron gas. It is revealed that these ghost warriors are made of Destron gas and cannot be beaten unless the gas is neutralized. The heroes continue to lose against their foes. Frieza, Cooler, Turles and Lord Slug appear and engage the heroes one on one. When trying to destroy the final machine, Vegeta discovers that it is protected by an impenetrable energy barrier. The Saiyans, plus Piccolo, only have 72 hours to destroy these machines and find Dr. He creates a machine that will emit Destron, a gas that could destroy all life on Earth. He now plans to take revenge on the remaining Saiyans, Goku, Vegeta, Trunks, and Gohan. Lychee may be the last of the Tuffle people, a race that was completely wiped some time ago by the Saiyans.