Very impressive piece here. The atmosphere you build throughout the chapter is excellent, a calm that feels controlled, with the exception of the mysterious stranger. I also want to applaud you for treating that with subtlety: Micali notices the man enough to look twice, but doesn't overtly act as though she suspects anything wrong. It's easily attributed to wariness without immediately raising red flags to the reader. Even so, when the altercation comes later, there's a satisfying "That guy!" feeling. Even though we know nothing about him, it means something that we've seen him before.
Micali's relationships with the coworkers is well-represented, and when the fight breaks out, I like that it's quiet. There's no shouting, no slamming into all the furniture. Micali and the hitman both fight viciously but controlled. A smashing lamp and tussling across the floor is enough to bring Dom, though, which is a nice touch, although it surprises me that the others weren't immediately there with him.
It was going so well, until the one liner at the end.