Next, he walks into a room. From our perspective the area that Kirk enters into is actually facing a wall above the foyer end of the set below:
The panel with the "e" on it is the foyer wall - the lift to the side is a dead giveaway. Taking the set literally, Kirk must have entered through a door situated above the horizontal intermix tube, at the aft end of Upper Engineering. ...
However, we do get to see the aft wall of the upper level - that green octogon thing from the cancelled Star Trek Phase 2
series. Leaving the "trouble shot" aside for now, the octogan would seem to be the door from which Kirk originally entered the room - and there is a large black area in the octogon which might be a darkened entranceway
. What do people think about that?
Having seen some Phase II pictures of the original engine room like this one
(mirrored or not?) it looks like there actually is a door right next to the octogon wall panel, so there wouldn't be the need to rationalize an entranceway in
You can also glimpse that door just a few frames ahead of this screencap
Thus, the blue corridor used by Kirk in TMP to get to the upper level
of the engine room would actually extend to the stern (starboard side) and not
to the bow (and outside the ship).
Too bad that takes only care of the upper level's blue corridor.