Underworld (also known as Dude? Where's my set?) is
the Greek mythological version of the afterlife. a not-so beloved Season 15 story from 1978.
It's about a long voyage to a planet of subterranean cities run by an insane computer.
It is widely known for its guest director George Lucas and the excessive use of quality green screen.
I was honestly on the verge of falling asleep while watching it.