Dune is based on a complex imagined society set roughly 20,000 years in the future. The setting is the year 10,191, and human beings have spread out and colonized planets throughout the universe. On the planet Caladan, Duke Leto of the House of Atreides is preparing to leave for his new position as the governor of Arrakis, a desert planet with valuable resources of melange, a spice drug that is extremely popular with wealthy people. Leto and his family, including his concubine, Jessica, and his son, Paul, suspect a trap by their rivals, the Harkonnens, led by Baron Harkonnen. Leto decides to settle on Arrakis because of its rich supplies of melange, despite warnings from his men, including his adviser, Thufir Hawat, and his master-of-arms, Gurney Halleck.

The Atreides arrive on Arrakis and the duke quickly moves to secure the planet from a Harkonnen attack. His main plan is to enlist the Fremen, the tough natives of the Arrakeen desert, as soldiers and advisers. Meanwhile, Paul’s and Jessica’s special abilities intrigue the Fremen. Jessica is a member of the Bene Gesserit, a school of quasi-mystical witches with strange powers. The Fremen believe that Jessica and her son are saviors who have come to lead them toward creating a lush paradise on the dry Arrakis.

Dr. Yueh, a member of the Atreides house, betrays them. The Harkonnens arrive and wipe most of the Atreides out by using Sardaukar, the super-soldiers of the emperor, who is secretly helping the Harkonnens. The traitor, Dr. Yueh, hands Duke Leto over to the baron, but in his guilt he helps Jessica and Paul escape. Dr. Yueh places a secret tooth in Duke Leto’s mouth. Duke Leto dies by emitting poison gas from the secret tooth, in a failed attempt to kill the baron. Hawat and Halleck escape as well. Halleck joins the local smugglers while Hawat attempts to join the Fremen, but Hawat is captured by the Harkonnens. He then agrees to work for Baron Harkonnen as a Mentat, or thinker, while secretly plotting his revenge against the baron and against Jessica, who he thinks betrayed Duke Leto.

Dr. Kynes, a Fremen leader and planetary ecologist, orders the Fremen to find Jessica and Paul. The Fremen capture and then quickly accept Jessica and Paul as their destined leaders. Jessica becomes their reverend mother, while Paul is recognized as something close to a religious prophet. Paul takes the name Muad’Dib, a religious title that means mouse. As he matures swiftly following his father’s death, Paul discovers he has great powers above and beyond those of his mother. He can see into both the future and the distant past. His consumption of melange heightens his powers.

Two years pass. The baron, living on the Harkonnen home world, schemes to usurp the emperor, while grooming one of his own nephews, Feyd-Rautha, to take over the job. Meanwhile, on Arrakis, Paul has become very powerful and influential among the Fremen. He is both their secular and religious leader, like Kynes before him, but his powers are far greater than those of Kynes. He has a child with a Fremen woman, Chani, the daughter of Kynes, and his mother has given birth to Alia, Duke Leto’s daughter. Paul teaches the Fremen to fight using a special style called the “weirding way” and using the advanced fighting techniques of the Bene Gesserit. One day, the Fremen discover that the baron has abandoned his aid to Rabban, the nephew he assigned to rule over Arrakis. Paul and the Fremen make plans to raid the Arrakeen capital now that Rabban is cut off from the baron’s help.

Upon discovering the power of the Fremen, the emperor himself comes to Arrakis, along with his Sardaukar and the Harkonnens. The Fremen attack the emperor, quickly dismantling his spaceships while destroying the Sardaukar. In the battle, Alia kills Baron Harkonnen, and Paul’s young son dies in a raid. Paul demands that the emperor step down; Paul asks to marry the emperor’s daughter, Irulan, so that he may become the new emperor. Feyd-Rautha challenges Paul, citing the right of vengeance, and Paul kills him in a duel. Powerless now, the emperor agrees to Paul’s demands, and Paul becomes the new emperor.