Michael Keaton Teaches Dylan O'Brien To Kill In American Assassin Teaser

Michael Keaton is going to turn Dylan O'Brien into a killer in the new teaser for American Assassin. The movie, based on the best-selling book Consent to Kill by Vince Flynn, follows O'Brien as Mitch Rapp, a man who becomes hellbent on revenge after his girlfriend dies in a terrorist attack.

The teaser starts with Mitch talking to CIA Deputy Director Irene Kennedy (Sanaa Lathan) about the death of his parents, who perished in a car crash when he was 14. Afterwards, he had a number of disciplinary issues, getting kicked out of three boarding schools. However, his life seemed to have been turning around when he met his girlfriend Katrina, who he had just proposed to when the terrorists attacked.

"You gave up everything after that, didn't you Mitch?" Kennedy asks him. The trailer then goes into a montage of Mitch training and researching to get revenge for Katrina's death. "No, not everything," he replies.

Kennedy decides to send Mitch to be trained by the best warrior she has ever known, played by Micheal Keaton. Mitch goes about proving himself to Keaton's Stan, who quickly defeats him in hand-to-hand combat but agrees to train him. "What is it you think we do here?" Stan asks Mitch. "Kill people who need to be killed," he replies.

The trailer doesn't reveal much about the film's villain, played by Taylor Kitsch, although it does hint that he's got a big, bloody, and chaotic plan that Mitch will likely be instrumental in fighting. However, he'll have to finish his training first, and Stan seems reluctant to let him go. "He's ready Stan," Kennedy says. "He's not ready, but he will be," Stan replies.

American Assassin will hit theaters on Sept. 15.