The Three Stigmata of Dr. Martin Luther King Jr.

In Philip K. Dick's novel The Three Stigmata of Palmer Eldritch, an intergalactic United Nations has organized residents of an increasingly uninhabitable Earth to colonize Mars. Reality is desolate. Colonists leave Earth with no chance of returning. The only escape comes through a dark matter chewing gum called "Chew-Z." The drug creates a world made up of three distinct moments: the taker's greatest missed opportunity, their most unacknowledged desire, and the worst moment of their life, all rolled into one. Each time the user ingests it, they get that much closer to resolving their deepest psychological wound.