I assume you are. You come to the end of the hall you look to the left it looks exactly like the hall you just walked down; you look to the right, it looks exactly like the hall you just walked down. They both go down 30 feet and end in a “T”. 

Quote from GR_Mustang >>

Fred 

Perception: 19

Stealth: 6

 Fred, you follow the others down the hall. Upon finding that the left and right passages look the same, you turn around to look back the way you came. But instead of seeing the hall open up to the naturally-formed room you were just in, you see the hall extend 30 feet then end in a “T”…

Progo looks both ways, turns back to the group.  "Fred, stay here with Savitri and be her eyes for the moment." He points to the right. "Progo will go this way and see what can Progo can see at the end of hallway and return. Thalron do the same down the hall?" Progo now sees the change in the hallway behind them. Progo stands up straight and scratches his head. "Progo maybe be lost" and point back for the others to see.

Fred does his best to keep his eyes on both.

Thalron will follow along with the experiment as best he can.

Progo whisper yells to Thalron: "Wait, Progo not sure about splitting up if hallways change after we go through them."

Thalron halts and hastily returns to the group.

"Do we see if going back gets us back were we expected or if we are stuck in a maze of some sort?"

Thalron takes out a small hammer (for a dwarf) and a chisel from his Mason’s tools. He inspects the near perfect cuts and joints.

”It’ll be a shame to mar such exquisite art, but then this could be illusory.”

”I think I’ll chip out a small section at the right hand turn indicating that we travelled to the right. When we approach the next T, I’ll look for my mark and also look for it across the way indicating we turned left. If there’s no mark, I’ll repeat the process. If my mark is already on the right wall, we’re in some kind of loop. If my mark is on the left wall indicating we turned left, then not only are we in a loop, but we were also flipped upside down. I have no idea what kind of madhouse we’ve stumbled into, but somehow we’ve got to gain our bearings.”

Each time he chips out a section, he will save the excised pieces in his palm to verify they’re not magically teleporting out of his hand to repair the wall.

"Maybe do some sort of unique marker, like a number or something incase we find a pattern"

“Aye, good idea!”

So tell me which way you are going. And someone roll a straight d20. 

Left after the T going "forward"

18

Thalron will mark the wall as described above except etch a number and new direction of travel.

The next corridor is 10 feet long then turns left at 90°.  

And around the corner come four kobolds. They look very caught off guard. They look gaunt and famished. They ravenously look at each of you and attack!!

Roll initiative

Kobolds: 8

Changed to initiative:

Progo:13

Initiative: 14

Savitri waited with Fred, " Hopefully they don't die."

Okay, so we just have two in the initiative?