Someone is LAUGHING. Not the maniac cackle of that horrible rat man who hid from her, nor her own deep satisfying chortle, nor the ugly false-sounding Caroline noises she is trying so hard not to remember. It is a... a "nice" sound.

Glados hates it.

She approaches the noise until she locates the noisemaker, at which point she arches a steely eyebrow - a motion she's now accustomed to enacting on purpose, and which she tolerates for its subtlety.

"What is so funny," she demands.