Michael Fassbender went into preparation for The Killer head-first. He recently spoke about the insane preparation he did for the David Fincher film.

In a pre-SAG-AFTRA strike interview with Empire, Fassbender called Fincher's The Killer “The type of film I was salivating to do.” He followed that up by telling Empire that he trained for 10 weeks getting into fighting shape. Additionally, he learned to assemble a sniper rifle “with ease.” He also read up on real-life killers to further understand their psyche.

“There's just trying to understand the mind of a sociopath,” Fassbender said. “I try and put together a lifespan, to where the character is now.”

The Killer is also based on the French comic book series of the same name. Fassebender said, ” What I loved about the comics is there was a lot to pull from.” In the film, Fassbender plays an assassin who gets entangled in a manhunt after one of his hits goes wrong.

David Fincher's film premiered at the Venice Film Festival earlier this month. Netflix will distribute the film, his second straight feature film to be distributed by the streaming service. His last film, Mank, was nominated for 10 Oscars. Previously, Fincher had directed the likes of Seven, Fight Club, Zodiac, and The Social Network.

Michael Fassbender is a two-time Oscar nominee for roles in 12 Years a Slave and Steve Jobs. He previously starred in 300, Inglourious Basterds, Prometheus, X-Men: Days of Future Past, and Assassin's Creed. This fall will be a busy one for Fassbender, as he will star in Taika Waititi's Next Goal Wins as well as Thomas Rongen.

The Killer will be released on October 27 in limited theaters and November 10 on Netflix.