The cast members of Tom Cruise's new sci-fi movie Oblivion have been sworn to secrecy about the film's plot and their characters in a bid to keep the twists and a climactic big reveal from spoiling the cinematic experience for fans. Journalists who caught preview screenings of the blockbuster, which also features Morgan Freeman, Olga Kurylenko and Nikolaj Coster-Waldau, had to sign release forms promising not to review the film or reveal any storyline points until 10 April (13), and the Game of Thrones star admits there was a veil of secrecy over the entire project like nothing he has ever witnessed. Coster-Waldau says, "I got this memo from Universal, the studio, basically saying you can't talk about the movie, you can't talk about your character." And studio executives were also keen to protect the privacy of their stars. The actor adds, "They also said, 'Don't talk about the private lives of any of the other actors (on TV chat shows).'"