Michael Keaton Mentors Dylan O'Brien in the Art of War in First 'American Assassin' Trailer

American Assassin stars Dylan O’Brien as a professional killer in training, under the guiding hand of Batman himself, Michael Keaton, in the new film from director Michael Cuesta (Roadie, Kill the Messenger). O’Brien’s character, traumatized by the sudden death of his girlfriend in a terrorist attack, wants to hone his lethal skills so he can properly hunt down those responsible for taking her life. While struggling with his huge loss, he’s recruited by Sanaa Lathan’s CIA bigwig to work with Keaton’s cagey mentor, whose initial skepticism about his new charge appears to soften as the new trailer (watch it above) goes along. The intense first preview features plenty of shots of O’Brien both reloading his weapon like a killer possessed, and calmly explaining his murderous intentions. American Assassin (based on Vince Flynn’s 2010 novel) arrives in theaters on Sept. 15.

Michael Cuesta’s ‘Kill the Messenger’: Watch a trailer:

Read more from Yahoo Movies: