Q is glad to drop the matter as it only serves as a reminder of what an utter git the Sirius he knew was.
Q nods appreciation of the spell then hesitates. He's loathe to go over this again, but if there's even the remotest chance that some bit of Voldemort remains with him, Sirius deserves to know. So he can deal with the problem should it arise. "Right," he says flatly, trying to keep his voice steady. "I was possessed by Lord Voldemort. He needed me to get the Philosopher's Stone so he could come fully to life again and make the elixir so he'd live forever. He also wanted me to kill Harry Potter." He splays his hand over the back of his head. "That's why my head looks like it does. His face was here."
"Well yes, I suppose, but I can't just take it," Q is appalled by the idea. "I'll have to tell Severus why I want it. And since that's part of the process, I think I should, whether or not you did it."
Q grins. It's obvious Sirius has no idea what he's talking about. "Sorry. Just using that as an example of teaching someone something. I'll play it for you sometime so you'll understand what I mean."
"Really?" Q is delighted. "Well, you remember when Dorothy threw the bucket of water over the Wicked Witch and she melted? Changing with Polyjuice is kind of like that, especailally if you're watching." He refrains from telling Sirius that seeing it done for the first time made him throw up. "It feels very weird around the ears." He nods. "Makes sense. Rule number one: Don't panic."
"All right. That sounds doable." He looks around. "Do you have a kitten handy?" He's not joking, not really.
*giggles* Oh dear. Just wait until Q starts singing! *snort* According to Lex, Q was the Muggle Studies Prof before he did DADA. I haven't exactly embraced that, but it does fit in with my character of Q. Though mine knows Muggle things for a completely different reason, which may or may not come up.