Jade vault trap poisoning undead

A Four-Way Intersection Two wide corridors intersect here, leaving you with the choice of all four cardinal directions. To the south, you see a wide staircase leading up into a faint light. In all other directions, the passages lead into darkness which your light won't penetrate. As you stand pondering your options, you notice the floor is marked with a strange sigil. Emanating from it are inch-wide lines of inlaid gold, silver, and jade. [Exits: north east south west] A large bubble floats around the room. A large bubble brushes up against you and explodes! You choke and gag on the contents of the bubble. You shiver and suffer. Luckily, you are immune to that.