Silly Lan.

Lan has spent the last 5 minutes literally laughing out loud. 

Why?

She had even gone as far as admiring the artist's attention to detail. The need for a keep out sign obviously to prevent any intruders from introducing fresh air and diluting the noxious fumes was a clever thought. Also, copious layers of insulation to ensure the gas perpetuates within that enclosed space instead of permeating to the outside world. Obviously.

This was all before she realised it wasn't as she had read. AHAS.