Checking the three doors, Arngen (with Grolvus assisting) notices nothing on the first, the udisturned door to the North. Moving to the South-East one (wherein the earlier party ventured), Arngen smiles as he notices that whoever went through disarmed, then reset some trap. Looking closer, Arngen traces the faint outline of
a stone that doesn't sit right in the stones surrounding the Door. This probably triggers some sort of Pit Trap or Falling Trap.
Grolvus whispers at Arngen's ear 'It's a Pit, I just found the edge' The Drow looks back to see Grolvus marking the edges with chalk. Arngen easily disarms the trap.
The third door seems safe, as Arngen detects no Traps.