"Allergies," repeats Glados. Yes, exactly. An allergy to this entire situation. "Yes. That must b-"

Aaaand there she goes again.

So. It isn't simply untruth. Mistaken theories, such as Mako's, are fine - but sarcasm, intended obfuscation, is not. How wonderfully specific.

This is going to be difficult to avoid.

But potentially useful, if she determines there's anything to learn from other people. If everyone is equally afflicted, that is. She can't tell yet, with Mako. In any case, it's best not to let on what she knows.

"What sort of world do you come from?" she asks. An inelegant subject shift, but she's a robot in a hurry.