[Della's got her back to whoever the newcomer is-- she's used to dealing with them by now, they always ask the same questions but she likes being around to help, anyways. It's kind of just routine at this point, so she doesn't even bother turning around when she answers.]

No, sorry, I've been looking into it but it seems like it's stuck tight. But if I figure something out, I'll-- Uncle Scrooge!

[Yeah, her brain took a bit to catch up with her mouth, there, but she recognized the voice well enough after a while. She whirls around on a heel, throwing herself at him suddenly and wrapping her arms around his neck before pulling back abruptly, mind already racing again.]

What are you doing here? [She holds up a hand immediately after she's asked it.] Wait, never mind, I know how you got here. I just wasn't expecting to see you!