Trick Or Treat
The Doctor paced the control room impatiently, wondering what was keeping Donna. She didn't normally take this long to get ready.
"Oh dear lord" the Doctor muttered, when he saw what Donna was wearing. She was dressed as a little girl, complete with a blonde wig done in braids. "What are you wearing?" he asked a little louder, so she could hear him.
"It's my costume, silly. I'm Lilith" she told him absently. She was looking distractedly around the control room, as if searching for something.
The Doctor's curiosity reared it's head, and he had to ask "what are you looking for?"
"My goody bag. What else?" Donna replied in a tone that implied he should have known, and what a silly question it was.
"Oh, of course. Why didn't I know that?" The Doctor then continued "why are you looking for a goody bag?"
"To put sweets in. How else am I supposed to carry them? Although, your pockets are bigger on the inside, so I guess I could put them in there. Only problem is I'd probably never see them again, so maybe not."
Adding everything up, the Doctor was beginning to get a nasty thought. A costume, goody bag, lollies, the 31st of October...
"Ahh, found it! Let's go spaceman, those sweets aren't going to collect themselves you know."
"We're going trick or treating, aren't we?"