The teaser for “Dune: Part Three” made a splashy debut, with director Denis Villeneuve and the movie’s stars Zendaya and Robert Pattinson gathering to preview the next chapter. The latest installment of the sci-fi franchise picks up 17 years after “Dune 2,” with Paul Atreides, played by Timothée Chalamet, as emperor and reluctant messiah, and the trailer hints at both sweeping war and personal turmoil. In a tense moment, Paul says, “The more I fight, the more enemies fight back. I’m doing the best I can to protect my family.” The trailer also introduces Pattinson’s shape-shifting villain, culminating in Paul’s stark declaration, “I’m not afraid to die… But I must not die yet.”