A possible secret door in 2-2 that refueses to be opened

[Taxxi]

There's a floor that goes down rapidly so damages you if you do not cast suitable spells such as feather fall in 2-2.

The thing is, if you fall in the place, look back and try to open the back wall, then it says it should be opened somewhere else, indicating that it is a secret door.

The problem is that I've searched every possible spots but there doesn't seem to be a lever to open the door. So I'm guessing that it can be only opened by those thievery characters or it's just a false secret door.

Veteran players would know that there are so many secret doors in this level. That includes one secret key that can open two secret doors, which means unless you have stealing ability, you can only choose just one of them. So I think it is reasonable to guess that the door can be only unlocked by thievery characters.

Has anyone unlocked the door? What was inside of the door? I'm curious lol

[peewee_RotA]

I think you're talking about the crossbow bolt closet.

There is a really cool secret "pattern" in that level. You have to get the key from the first secret room (which locks that room), then you use it in one of 2 places. Either to get the bolts (extremely valuable to rogue and archer), or to get the amulet of strength (incredibly overpowered). Only the rogue can get both. I believe that the amulet door can't be picked, though. So you have to get it first then go pick the bolt closet.

*Edit*

After rereading the post, I think I mistook where you were describing. The center room between the switches that has a pit trap does not have any secret doors. But the first door that lets you into the pit room shares a linedef with the pit itself. As you can see on this screenshot, there is an action number (13 to be specific) associated with that linedef. Interestingly, it is not the same action number as the south side of that door (which is action 4)

It must be a message for if you somehow got into that room before hitting the first switch to open it.

https://drive.google.com/file/d/0B53xwpRlaEsdaU44LXRiQk1MVTA/edit?usp=sharing

[Taxxi]

I think you're talking about the crossbow bolt closet.I believe that the amulet door can't be picked, though. So you have to get it first then go pick the bolt closet.

Oh, so is that the only room that cannot be picked? Thanks for the info

I myself also tried to figure out what was going on after reading your post, and discovered that when you go inside the pit room, the door you got through becomes closed. I never knew it since I just simply killed everyone inside and then got out of the room, always. So somehow the wall beneath the door also got assigned the status 'locked' and that was the reason why all my effort to get inside there was futile  IIRC there are several places that have similar problems to this one, but they were to some extent understandable since I knew that a closed door was right above or beneath the wall.