Krane introduces his evil cohort, Dr. Gao, who reveals his development of liquid bionics in their plan to conquer Donald's space colony and replace Earth's soon-to-be annihilated population with a bionic civilization. With Donald under Krane's mind control, the teens destroy the dome and flee back to Earth in the intergalactic spacecraft, taking Donald, Tasha, Perry and the colonists. As Krane comes after them in a weaponized shuttle, Dr. Gao teleports aboard and puts Leo under his mind control. Following a decisive space battle against Krane and a control room scuffle against Leo and Dr. Gao, it falls to Adam, do or die, to save Earth from Krane's atomic missile sent to trigger a nuclear winter.
—statmanjeff