The Emperor amasses a huge invasion fleet above Arrakis to wipe out the Fremen and regain control of the planet. He has "The Beast" Rabban beheaded and summons Baron Harkonnen to explain why spice mining has stopped. Paul launches a final attack against the Harkonnens and the Emperor's Sardaukar at Arrakeen, the capital city. Riding atop sandworms and brandishing sonic weapons, Paul's Fremen warriors easily defeat the Emperor's legions. Paul's sister Alia mortally wounds Baron Harkonnen, who is sucked through a breached palace wall and into the mouth of a sandworm. Paul confronts the defeated Emperor and fights Feyd-Rautha in a duel to the death. After killing Feyd, Paul demonstrates his newfound powers and fulfills the Fremen prophecy by causing rain to fall on Arrakis. Alia declares him to be the Kwisatz Haderach.