A/N: Prompt was the Time Twins playing dressup in the vast wardrobe collection of past Doctors/companions. They are around ten when this takes place.
It was the weekend and Alison and James were bored.
Usually weekends were not boring at all, but when they went to go pick up Mum, they found out that she had caught a cold from one of her students coughing all over everything. This meant that they were having a weekend in, though it also meant that Dad was waiting on Mum and making sure she was doing alright, leaving the kids to generally fend for themselves.
"Auntie Idris? We really wanted to go sledding on that snowy planet with Mum and Dad," Alison frowned up at the TARDIS core in the control room. "Do you have a room where it snows enough where we can sled?"
The ship hummed in reply.
"That's nice, but Mum said she was going to have to get us new winter stuff because we outgrew the rest," James mentioned. The TARDIS whirred again, chidingly this time. "But there's nothing in our wardrobe!"
The lights around the children dimmed, the only light around them being the emergency ones that lit the floor's edges. When something like this happened, it was usually because the TARDIS wanted to lead them somewhere, so the kids ran over to the corridor, stopping directly where it branched off into a couple different paths.
Only one of the paths was lit—it was time for an adventure.
Heading further and further into the ship, the siblings followed their aunt's directions until they came to a door whose frame was all brightly lit. The rest of the lights went on and the kids knew they had reached their destination, not that they knew where it was. They stepped forward and the door opened to reveal a large room that had many mirrors and wardrobes, along with a couple chairs to sit in, and even some curtained stalls in the very back.
"What is this place?" James wondered.
"I dunno, but it's Auntie Idris, so it won't be that dangerous," Alison replied. She walked up to a wardrobe and opened it, scrunching up her nose at its contents. "It's just clothes."
"Clothes? Really?"
"Yeah, look at this," she said. She pulled out a hanger holding cricket whites and a brimmed hat to present to her brother. "Didn't Da say once he used to fancy something like this?"
"He used to fancy wearing a lot of things," he shrugged. James went into another wardrobe and pulled out a large, blue-violet pelt that covered him from head to toe and then some. "This looks like it was supposed to be a puppet-monster skin."
"Better than that fur coat Da used to wear," Alison chuckled. She opened another wardrobe and broke into giggles. "Here it is!" She put it on and laughed before letting out a sneeze. "I wonder what sort of animal this is."
"Probably a life-like synthetic, knowing Dad," her brother said. "He told me once it was a yeti—bet that's a load of crock."
"Look at this!" Alison gasped, going into another wardrobe. She pulled out a pair of yellow boots that went up past her knees and a dress that looked like it would have been too short had she only been a couple years older. "Dad ran with some weird people if this is what they used to wear. It almost looks like some Halloween fancy dress!" She then ran into one of the curtained stalls and changed into the outfit, giggling as she did so. "This is wild!" When she drew open the curtain to show her brother, she saw that he was no longer in sight. "Jim, where'd you go?"
"I'm in here," he said from the other stall. A few moments and he opened his curtain to reveal his outfit: a black turtleneck and a kilt. "Found Uncle Jamie's clothes."
"Wow! That looks good on you!" She walked over to another wardrobe and peeked inside, gasping in delight. "More of Da's old things!" Alison nearly tripped in her boots as she took a new armful of clothes back to the changing stall, coming out wearing flared dark trousers, a white frilled shirt, and a green velvet jacket.
"I still don't understand green velvet," James said, shaking his head. "Do you think the red one will go with what I'm wearing?"
"I dunno—try it." She watched as he reached into the wardrobe and pulled out another velvet jacket, putting it on. "Nope."
"Then let's see what does…"
It was only after Clara was fast asleep did the Doctor realize that he hadn't heard from their children in hours. He checked their rooms first, then the library, then the study, the console room, the kitchen, the park… it wasn't until the TARDIS nudged him along did he find them in a place he hadn't been in a long time: a room that provided him with different weather conditions for experiments. It was gently snowing while the twins were trudging up to the top of a hill, James pulling a sled behind them.
"Hey! You two get over here!"
"Coming Dad!" the tweens replied. They took the sled to the bottom of the hill and ran over to their father, who could now properly see what it was they were wearing: James was in his old brown coat and extra-long scarf, while Alison was in a pink version with a very long white scarf.
"Where did you get those?" he asked, furrowing his brow.
"Auntie Idris gave them to us," Alison said.
"Oh, well I was just about to ask you two if you wanted lunch and…"
"Yes!" the kids cheered, scurrying out the door. The Doctor followed, glad he knew precisely how to get his children's attention.
A/N: The blue-violet furry cape is actually part of the Thal wardrobe in the movie Dr. Who and the Daleks, which is the movie version of the introductory Dalek story with a larger budget, Technicolor, and some changes to the Team TARDIS 1963 dynamic (for one, Barbara and Susan are sisters). It's also notable for being the first of two movies with Peter Cushing, the Grand Moff Tarkin himself, playing the Doctor in a way that makes me maintain that it's a viable AU of the main canon, sort of like how there are apparently a bajillion alternate realities when it comes to Ace's adventures post-cancellation. It's campy, but damn it, I love the thing wholeheartedly (and it was weird watching the TV version of the story because of it, as I saw the movie first). It also feels like I've gushed about this movie before, but I don't care—it deserves it.
Another thing to note is that James and Alison end up dressed as the Fourth Doctor and Romana II from the story Destiny of the Daleks. They also found clothes from the Fifth Doctor, Second Doctor, Jo Grant, Jamie McCrimmon, and Third Doctor, in that order.