I feel this song as the emotions and thoughts of a protagonist, as he follows/spies on individuals that can best be described as dangerous.
the... cellos? tubas?... low notes, keep a feeling of tension and mystery, the rest of the instruments giving that classic noir goodness. The keys in the middle of the sounds keeping the atmosphere consistent enough for the blunt transition to work.
The transition is as if the protagonist was knocked out, bringing a flashback of him and a lover. The details are fuzzy, but it's mostly beauty and romance, some notes bringing a sense of fading.
The low notes are pretty much gone taking with it the other instruments and with them the noir. The thin strings keeps a dreamy quality that always entrances me no matter where I hear it. (I got to learn how to do that.) Bu this dreamlike atmosphere feels like the song reached an intermission, and by 2:36 the soft quality begins to tire me out, like it's wasting time, "is this intermission going to be solved" is probably the words that fit the reason why i thought that.
At that moment, 2:36, I feel some instruments should die out or get softer, so it feels like it's coming to a close instead of feeling like it extends its welcome and shows overindulgence in the Mile Davis inspired smoothness of the part. Then again, I gave a specific number, but that's just me saying that it feels too long, but just a tiny bit. Maybe it'll make the slight disappointment of knowing it'll never go back to the first half naturally happen in more of a "oh, it's done" instead of "how long is this song?"
It's a weird tradeoff, but i like the decision of making the experience somewhat inconclusive and the thing about such a decision is that it'll always be a mixed bag where opinions will be all over the place. my opinion, i think all this needs is a bit of trimming.
I didn't say anything about the beginning because i have no clue on how to change it so it melds together with the other half with more than one instrument. I'll leave that to your judgement.
Mixing wise it sounds very nice to me (though I'm using laptop speakers)
aannnd yea Sorry if I couldn't help with anything more specific.