Dune

The spice, or melange, is the most valuable and coveted substance in the universe of Dune. Harvested on the surface of Arrakis, spice is a hallucinogenic drug that allows users to glimpse visions of the future. These glimpses make space travel possible, meaning that the Spacing Guild is both addicted to spice for its drug-like qualities and for high prices it allows them to charge for space transportation. As such, many of the influential characters are addicted not to the spice itself but to the power and influence that it grants them via space travel. The spice is a metaphor for control: Whoever controls the spice, controls the universe. The Baron, a man who lusts after control and influence at any cost, is willing to sacrifice decades of income to take back Arrakis. Just like the Spacing Guild members who are addicted to the spice itself, the Baron is addicted to controlling Arrakis and enjoying the influence and power that such a position grants him. Spice is more than just a resource; spice—and whoever controls spice production—represents the real power in the universe, meaning that the fiefdom of Arrakis is hugely coveted. Many readers view spice as a metaphor for crude oil and the violent conflicts fought over its control, particularly in the Middle East.