Planet, Crossroads of Destiny
The 999 approached the Planet called Crossroads of Destiny, where its blue satellite planet was about to go extinct. The planet was inhabited by a people who returned to a survivalist society when it ran out of natural resources. Tetsuro met Yaku, a weak hunter who was experimenting with new weapons. When his companion Aya decided to leave him for Mu, Yaku went to confront Mu, but was badly beaten. However, he managed to kill a saber-toothed tiger with a crossbow he constructed, saving Aya and Mu. Though Mu laughed for his lack of physical strength, Yaku was satisfied that a new age of knowledge had started with him.
Aired 11/09/1980EP 88 - Planet, Crossroads of Destiny

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)