The Graveyard at the Bottom of Gravity: Part One
The 999 falls into the Sargasso, where they find the remains of the 333, a missing train. Traveling aboard, Tetsuro, Maetel and the Conductor find only skeletons. A woman aboard the train, Ryuzu, reveals herself, saying that she sped up time on the train which killed everyone. Through her threats, she takes a hold of Tetsuro and departs the train's remains with him.
Aired 26/10/1978EP 7 - The Graveyard at the Bottom of Gravity: Part One

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)