David Fincher’s “The Killer” stars Michael Fassbender as an assassin for hire. He’s very good at his job, which is why his services are so expensive.

Though that sounds like an exciting profession full of action every minute, the reality is probably more like the one portrayed here. Fassbender spends a lot of time in the extended first sequence waiting around for his prey to show up, while in voiceover he explains the intricacies of the job and the aphorisms he keeps repeating to himself. “Fight only the battle you’re paid to fight.” “Anticipate, don’t improvise.” “Never yield an advantage.”

As a fan of process, I enjoyed watching him cool his heels over the course of a couple of days before finally lining up the shot and pulling the trigger. Unfortunately, something goes wrong and he has to escape. But when he gets home, he discovers his home has been broken into and his girlfriend assaulted. From there on, “The Killer” becomes a revenge movie, as Fassbender tracks down the people responsible.

There’s a great scene late in the movie with Fassbender and another professional assassin, played by Tilda Swinton. Their encounter doesn’t involve a gunfight or hand-to-hand battle. Rather, we watch him surprise her by sitting down at her table in a nice restaurant. She immediately knows who he is and why he’s there, but Fincher and screenwriter Andrew Kevin Walker give Swinton some great lines while Fassbender stays mute. They’re both icily cold, but it’s the way Swinton speaks (and tells a joke about a grizzly bear) that makes the scene spectacular.

The rest of the supporting performances are also quite good, especially Kerry O’Malley as the quick-thinking assistant to the man who sends these contractors of death out into the field to execute without needing to know why.

To be honest, I wasn’t sure how I felt about “The Killer” when it ended. But it stuck in my brain for a few days before I decided I liked it enough to give it a 7 out of 10.

Now streaming on Netflix.