"Um," Q begins hesitantly, "I'm not trying to be flip Severus, but isn't water the ground state of everything? Except olive oil and gasoline?" He blinks once or twice. "I don't think it's chicken fat," he offers tentatively. "I mean, it'd melt in the heat. Sort of a messy lamp." He smiles.
"Well, I can explain that," Q tells him. "And apologise if I have to. I know," Q shrugs with his shoulders, not having mastered the art of expression-shrugging. "But what if she's too busy?"