Africa the Great Dark Nebula: Part Two
While experimenting on the 999, the Ghost Hoppers put the three to a nearby jail. One of the Ghost Hoppers explained that they colonized Kilimanjaro two years ago, and eradicated the local aboriginal population. The artificial suns (which became the triple sun) they launched resulted in their two-dimensional appearance. The Ghost Hopper Queen's mothership appeared to halt the experimentation. She restored the 999 and released the three. The Queen, disgusted by the unethical pursuit of science by her own people, also left the Nebula.
Aired 01/05/1980EP 73 - Africa the Great Dark Nebula: Part Two

Galaxy Express 999
After witnessing the death of his mother and being left for dead at the hands of Count Mecha, ten-year old Tetsuro Hoshino is awakened by a mysterious woman, Maetal. In exchange for only his company, Maetal offers him the ride of his life on the Galaxy Express 999. It is said that those who travel aboard the legendary train to the end of the line can receive a free mechanical body and with it, immortality.
Impoverished and alone, Tetsuro leaps at the opportunity and joins Maetal on a quest that will span the cosmos. As the Galaxy Express 999 makes its way across our solar system and beyond, Tetsuro is drawn deeper into a dangerous universe where peril lurks at every stop.
(Source: Discotek)