From the liner notes

With fuel prices skyrocketing, the Planet Express crew sets off on a dangerous mission: to infiltrate the world's only dark-matter mine, source of all spaceship fuel. But deep beneath the surface lies a far stranger place... a medieval land of dragons and sorcery and intoxicated knights who look suspiciously like Bender. So park your hover-car and saddle up your unicorn for Futurama's grandest adventure yet!