The Atreides are unable to withstand a devastating Harkonnen attack, supported by Imperial Sardaukar disguised as Harkonnen. Captured, Duke Leto dies in a failed attempt to assassinate Baron Harkonnen; Paul and Jessica escape into the deep desert. They manage to join a band of Fremen, ferocious fighters who ride the giant sandworms of Arrakis. Paul and his mother quickly learn the ways of the Fremen, while teaching them the Bene Gesserit method of fighting. Jessica becomes a Reverend Mother, taking the concentrated spice while pregnant with her Duke’s second child. Her daughter Alia experiences all that her mother does from the spice, gaining wisdom before even being born. Living on the spice diet of the Fremen, Paul's prescience increases dramatically, enabling him to foresee future events and gaining him a religious respect from the Fremen, who regard him as their prophesied Messiah. As Paul grows in influence, he begins to plot revenge against the Harkonnen rule of the planet under his new Fremen name, Muad'Dib.