Departure Ballad
Tetsuro's mother is murdered while the two of them travel through the snow by the villainous Count Mecha. Before she dies, Tetsuro's mother tells him to go to the planet Andromeda where he can get a machine body and not die like she did. Tetsuro passes out from the cold but is rescued by the mysterious Maetal, who gives him a pass to the Galaxy Express 999 for free under the condition that he will travel with her.
Aired 14/09/1978EP 1 - Departure Ballad

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)