31G WINDING CORRIDOR. As either metal door that is used to enter this corridor is opened, a “whooshing” sound will be heard. Once the door closes again, the corridor will begin to fill with laughing gas. In the second round, characters must save vs poison or begin laughing uncontrollably. In the third round, they must save vs poison or fall unconscious.
The “whooshing” sound is caused by the evacuation of the gas when either door is opened, replaced with normal air. Unconsciousness from the gas will last for 1d4+1 turns after the character is returned to a normal atmosphere.