In the Imperial audience chamber on Arrakis, Baron Vladimir Harkonnen waits anxiously before the Padishah Emperor Shaddam IV, surrounded by Sardaukar, court attendants, Guild agents, Princess Irulan, and the Reverend Mother Gaius Helen Mohiam. Shaddam questions the Baron about Thufir Hawat, and the Baron explains that Hawat was sent to infiltrate Muad’Dib’s camp and will soon die without the antidote to a latent poison.

The Emperor then presses the Baron about the Fremen, the south polar regions, and the possibility that the supposedly uninhabitable south hides organized human activity. Shaddam reveals that a Sardaukar raid there nearly failed against a force of women, children, and old people, and he presents one captured prisoner: Alia, Muad’Dib’s young sister. Alia calmly insults the Baron, announces that she allowed herself to be captured because Paul’s son was killed, and reveals herself as the daughter of Duke Leto and Lady Jessica.

Alia’s presence terrifies Reverend Mother Mohiam, who calls Alia an abomination and realizes that Alia contains ancestral memories in a way the Bene Gesserit fear. Alia demonstrates a strange mental contact with Mohiam and refuses the Emperor’s demand that Alia command Paul to surrender. Alia tells Shaddam that Paul already knows where Alia is and that Muad’Dib is coming.

The hutment shakes as Paul’s assault begins under cover of the storm. Shaddam orders a retreat into his ship and commands that Alia be thrown to the storm, but Alia backs into the Baron’s arms and kills him with the Atreides gom jabbar, calling him Grandfather. As shields fail, the ship is damaged, dust fills the chamber, and Alia escapes into the battle to fight in the Fremen way.

Outside, the Emperor and his forces witness an impossible sight: Fremen riding a massed wedge of sandworms into combat against the Sardaukar. The Sardaukar recover from their shock and engage the Fremen on the plain, while the Emperor is forced into the ship behind a defending bodyguard. Inside, the Emperor sees that even the Guild agents are uncertain, and he and Mohiam recognize that their remaining option is treachery, prompting Mohiam to order Count Fenring summoned.