The Conductor was a mysterious god, and the driver of the Train, an equally-mysterious primordial engine of planetary proportions that pulled the worlds in its path into its orbit. After the Conductor's mortal servants and facilitators stripped a world of resources, the Conductor grabbed the planet with its wand and pulled it into the mass of energy that was the Train's furnace to fuel it. The Conductor's labor is endless, and it has driven the Train since before its first memory.
After allying himself with the lesser demons Mog'rys and Borss, the villainous Nebulon escaped from Hell. Using a humanoid form, he moved from world to world aboard the Train, killing the Conductor's familiars before revealing his true form and attaching himself to the Conductor's mind. Nebulon then exerted his will on the Conductor to make him shift the Train's course to Earth.
When Galactus and the Silver Surfer stumbled into the Train, he eventually discovered Nebulon's presence, and attempted to fend him off to no avail. He was joined by Namor, who had been rescued by the Silver Surfer's Surfboard from Vodan, an alien planet nearby that was eventually pulled into the Train. They were eventually joined by the Hulk and the astral projection of the Doctor Strange of an alternate future in which the destruction of the Train to stop it from destroying the Earth doomed the planet either way due to the radiation emanated by its destruction. While the Hulk distracted Nebulon by bludgeoning him with the Sufer's board, since the board disrupted the creature's ectoplasmic essence, Strange's astral form slid into the macro-mind of the Conductor. He exerted all of his will to induce a spasm on the giant, causing it to jerk its wand and fling Vodan, the planet on its grasp at the time, into the void of space. This movement caused the Train to shift a fraction of a degree. At the speed and distances involved, this was enough to set the Train off course and miss the Earth. Since this caused Nebulon to fail a deal he and his benefactors had with Mephisto, the demon lord appeared and claimed their souls, detaching Nebulon from the Conductor's mind and freeing it from the monster's influence.
- According to Galactus, the Train is from a time and space that is beyond even his understanding, to the point he originally thought it to be only a myth. He also considered the Conductor to be a god unlike any he had seen before.