Trapped In Passage

[shepherd]

Hi

I was in a level where it seems you have to send post via a vacuum tube to a central location. I sent the first post (from some "frozen storage" room, I think), walked into the passage on the side and was killed by a creature. Upon continuing the game I was able to exit the passage, got up to the start of the level (where there is a dentist-type chair) and somewhere fell through the floor (not the first time that I've fallen through the floor, but it hasn't been a serious problem before).

So I saved & exited and went back into the game. Now I'm stuck in the earlier passage (between frozen storage and the main room, where I died), only both ends are closed. There's nothing to do in the passage and I can't exit from either end.

I've attached two screenshots which illustrate the two ends of the passage that I refer to being closed. A quick search did not reveal any info on this and I did not want to dive too deep into it for fear of spoiling the experience.

If I am being a noob and there is a legitimate way out of the passage in this scenario, please let me know and I'll go searching for it. Otherwise, any ideas on how I should proceed?

Thanks.