Sometimes the best commercial for your movie is … more movie. That's the strategy for director Ridley Scott's <i>Alien: Convenant</i>, which was introduced to fans last year with a scary red-band trailer, and is now being sold with this short "prologue" directed by Scott's son, Luke Scott. The film's cast — including Michael Fassbender, Katherin Waterston, Billy Crudup, and Danny McBride — is on board for the prologue, which was produced by Scott's production company RSA Films.