No traps... checking behind it reveals a small passage, about 10' wide and 5' high heading south. The passage looks rough-hewn, not like the rest of the level that you've seen so far.
Blocking the door with the bunks, you duck/crouch down (except Rondo) and head down the passage. It goes for about 20', turning slightly southeast, then ends abruptly.
Checking behind it reveals a passage going northeast-southwest, whose "structure" is back to the "regular" form (of the type of the room and passages before it; not the hand-hewn one that the secret passage seems to be made of).
Si'Nat takes the the silence behind him as assent. You head southwest for about 30' and it turns south. You go 20' when you come to a 20' wide opening to the west leading to a huge room with torches. The passage continues south.