A noir Hero's journey?

The key if I'm not mistaken, is the hero traveling from his 'home' to discover his mission in another land. Closest I can think of is Blade Runner, where the Harrison Ford character has to sort of infiltrate the world of the synthetic humans to bring them back to justice. Does that make sense?

If it's a spiritual journey, it's easier: in Chinatown, Gittes is perfectly content to stalk cheating wives for money and have his shoes shined. But the Mulwray case drives him out of his content bubble and motivates him to help Mrs. Mulwray at risk of his own life.

I think most noir stories include an element of travel/infiltration of a foreign land even if that foreign aspect is just people and their behaviour rather than a separate physical place, like mario's examples above.

Did you see Brick? That was a noir detective story meets high school teen drama. There was no travel to another land for the hero but he did travel into an underworld that he had little knowledge of before. It certainly fits into the category of film noir with a modern twist.

I guess the distinction to make here is whether you're talking about an actual journey to another place or something a bit more metaphorical.

It may help to think of it no as Man Goes on a Journey, but a Stranger Comes into Town. Where the stranger is the noir hero.

The noir detective usually upsets the balance of someone else's life more than having their own lives unbalanced (although they are, of course).