"So where is he?"

"Oh, Mum, don't start," sighed Donna, exasperated. "He's just parking the TARDIS and getting changed, all right?"

Sylvia folded her arms indignantly, but caught sight of the expression on her daughter's face and subsided slightly. Donna pulled off her coat and shook her head vigorously.

"It's not snowing out, is it?" asked Sylvia. "It'd be nice to have a white Christmas for once. I...is that green snow?"

"Yeah," said Donna, examining a strand of her own hair at close quarters. "We just came from the Apogee Carnival on Antaria. It snows all year round, but you only get green snow during the winter, apparently."

Sylvia's reply was, perhaps mercifully, interrupted by the doorbell. Donna turned to answer it, but her grandfather bustled past her and pulled the door open, beaming.

"Doctor!" he cried, saluting. "Pleasure to see you again, sir! Merry Christmas!"

Donna sagged in the throes of a sudden attack of contact embarrassment. The Doctor was wearing a Santa costume and carrying a small but curiously lumpy sack slung over one shoulder. It wouldn't have been half as bad, she thought, but for the fact that beneath it all he'd elected to hang onto his sneakers.

"Don't say it," she warned, levelling an admonitory finger at him.

"Say what?" asked the Doctor, unshipping the sack and looking hurt. This expression faded as fast as it had come, however, and he grinned out of the false beard and extended a happy hand to Wilf, who grasped and shook it with just as much delight.

"Come in, come in, take the weight off yer feet," chirped Wilf, ushering the Doctor past and into the living room. Donna and her mother stared at one another for several seconds, and then followed.

The decorations in the living room owed more to Wilf's enthusiasm than to his skill and dexterity, and the threadbare tinsel was broadcasting the faintest air of desperation. Nevertheless, the Doctor seemed enthralled by it all. He dumped the sack in front of the fireplace and regarded the scene with bright, gleaming eyes.

"Nice," he said, cheerfully, "very nice! Very sparkly!"

"Thank you," said Sylvia, although Donna cast a sidelong glance at her mother's face and saw traces of bemusement there. The Doctor could be hard to fathom sometimes.

"Presents!" said the Doctor, bending to rummage in the sack. Donna tilted her head as he issued several pained and unintelligible mutters, and gawked in astonishment as he drew out a floridly wrapped parcel several times bigger than the sack from which it issued.

The Doctor straightened up to face three questioning stares. He frowned in puzzlement, looked at the parcel, looked down at his feet and then spotted the sack. Realisation apparently dawning, he looked back up at his audience once more and smiled brightly.

"Ah yes," he said. "Time Lord technology. It's like the TARDIS."

The stares continued in the same bewildered vein.

"It's bigger on the inside," he explained, carefully. "Anyway. Sylvia, this is for you," he said, handing it over. Sylvia took the parcel as if it were ticking, but the Doctor was already rooting in the sack once more, blowing a stray strand of beard off his lip as he did so.

"What?" he said, vaguely. "What? No, no, that's last Christmas...now, where are you?" he continued, reaching deeper into the sack. Donna watched as he plunged another arm into the sack, followed presently by his head and shoulders. The absent minded mumbling grew somewhat muffled.

"Doctor?" said Donna.

"Back in a mo," said the Doctor, sounding for all the world as if he were gripping something between his teeth. She heard him spit delicately, and then released a long held breath as he backed out of the sack with two more parcels in hand. There was a sooty mark on his cheek, about which Donna adamantly refused to speculate.

"Wilf, this is yours," he said brightly, passing over another parcel, this one long and narrow, "and yours," he went on, handing a small box to Donna.

She looked at her mother's and grandfather's presents with the slight but definite disappointment of anyone who has ever been left holding the smallest Christmas present in the room. Nevertheless, the Doctor's happy smile wasn't something she wanted to disturb, so Donna returned it with one of her own and pulled at the paper. It did not escape her notice that it was decorated with a pattern of Easter eggs, but she tried not to draw attention to the error.

"I hope you like it," he was saying. "Took me ages to find one."

The small box had a picture of an animal on the lid; despite a slight resemblance to a llama, it was of no immediately definable species, and she frowned briefly before opening the box.

There was a small, dull black stone inside, nestled in a network of silver filigree and attached to a chain almost as fine as a human hair. Donna plucked the diadem out of its nest of cotton wool and hung it before her eyes, where it turned lazily and glinted at her.

"It's a fragment of a Pelocosian comet," said the Doctor. "You'll find it glows in the presence of liars...or methane," he said.

Donna lowered the stone and eyeballed him levelly.

"So basically," she said, at length, "if I wear this on a date and it lights up, he's either fibbing or farting?"

Wilf had torn open his parcel and was holding a slim black telescope up to his eye and frowning through it. The Doctor grinned and held out a hand, taking it back and pointing at several notched wheels on the side.

"That's the magnification," he said, "which is infinite, by the way, so you can see all the way to the end of the universe. These five are filters, so you can also see in radio waves, X-rays, infrared, ultraviolet and gamma rays, just like a radio telescope. Good, innit?" he finished, and passed the telescope back to Wilf, whose jaw was now hanging loose.

Donna turned to see her mother opening a box and regarding its contents with small enthusiasm.

"Bath salts?" she said, flatly. "Well, thank you very much."

"Oh, they're not just any old bath salts," said the Doctor, eyes agleam. "Put one tablespoon of those in your bath and you'll look twenty years younger for a week."

Sylvia struggled for emotional equilibrium, then recovered magnificently and hugged the huge crystal jar to her bosom.

"Thank you," she said, this time much more warmly. "Anyway, I think it's about time I got that turkey on. Donna, sweetheart, will you give me a hand with the dinner?"

Wilf put down his new telescope and raised a hand smartly.

"You stay right there, love," he said proudly. "It's ladies' day off today, eh, Doctor? We'll do all the cooking."

"We will?" said the Doctor, looking hunted. He caught Wilf's eye and wilted. "I mean, yeah, of course we will. Point me at the kitchen, I'll get right on it!"

When Wilf had ushered the Doctor into the kitchen and closed the door behind them, Sylvia looked her daughter up and down with a jaundiced eye.

"So - where've you been gallivanting off to, madam?" she asked. "It's been two weeks and not a single call from you."

"Sorry," said Donna, tartly. "I couldn't find a phone box."

"You've been flying around in one!" snapped Sylvia.

"It hasn't got a real phone in it," said Donna, sighing dramatically. "I do wish you'd try and understand, Mum."

"Oh, so he can travel around in time and space but he can't put a phone in?" snorted Sylvia, scornfully. Donna folded her arms in unconscious imitation of her mother.

"It's Christmas Day," she said, "so try and be nice. Look, he did buy you a present. A really nice present," she added, glancing longingly at the bath salts.

Sylvia subsided.

"That's true," she said, picking up the jar and studying the soft silver crystals. "Tell you what, I think I'll go and have a bath while they're cooking. That'll surprise your old Granddad, won't it?"

Meanwhile, safe behind closed doors, Wilf and the Doctor were staring at one another in an apparently unbreakable deadlock. A raw, flabby turkey squatted on the table between them like a sacrificial offering, pimply legs akimbo.

"I thought you said we were going to cook this lot," said the Doctor, desperately.

"Yeah," said Wilf, "but I don't know how, do I? I thought you'd know how to cook."

"Me? Why me?"

"I dunno, I just thought you would," said Wilf, panicking. "Fine mess we've got ourselves into now, ain't it?"

"Okay, okay," said the Doctor, running both hands through his hair distractedly. "It can't be that hard. Let's have a look at the wrapper, shall we?"

He picked up the turkey wrapper, still sticky with pink juices, and ran an eye down the cooking instructions on the label.

"Says here it needs 20 minutes per pound," he mused. "So that's three hours, then. Can't be right, can it?" he asked, cocking an eyebrow at Wilf, who blanched.

"Er..."

"Tell you what," said the Doctor smartly, pulling out the sonic screwdriver. "I'll just speed things up a bit. Won't take a jiffy."

So saying, he dropped to his knees and yanked open the oven door, poking his head inside and grumbling thoughtfully. Wilf, trying to peer over the Doctor's shoulder, heard several sharp crackles and saw a brief flash of blue light, like an arc welder. The Doctor yelped in triumph and withdrew, grinning.

"There we go," he said, happily, "shouldn't take more than ten minutes now. Okay, bung it in."

"I think Sylvia usually stuffs it first," said Wilf, though he sounded doubtful.

"Really?" asked the Doctor. Wilf nodded. "Fair enough," the Doctor continued, shrugging, "let's see what's in the magic bag, shall we?"

He dumped the sack on the table and rummaged inside it, drawing out a large plastic bag. Wilf eyeballed it carefully before replying.

"Not that sort of stuffing," he said, eventually. "I think it's sage and onion or something like that."

"Oh," said the Doctor, looking bewildered. "Righto. Okay. Um. Tell you what, put it in the oven and we'll have a look later. Where's the pudding?"

Wilf, after a brief moment of confusion, managed to locate a brandy and sherry Christmas pudding in the cupboard. He hefted it in one hand and studied the label, pursing his lips.

"It says we have to steam it," he said, at length.

"What, we can't use the microwave?" asked the Doctor. "Nah, that can't be right. Give it here." He took the pudding, stripped off the wrapper and placed it reverentially in the microwave before turning the dial. In the midst of this, he paused and craned over his shoulder at Wilf.

"How long?" he asked.

"Er...five minutes?" said Wilf, helplessly. The Doctor nodded firmly and twisted the dial, watching as the pudding turned gently behind the glass.

"Okay, the turkey should be done now," he said, brightly, and only then turned to look at the oven. Tendrils of greasy yellow smoke were pouring out of the gap at the top of the door.

"Um," said the Doctor, but Wilf was already pulling on an oven glove and opening the door. The smoke belched out, free at last, at the head of a rolling cloud of exuberant steam. Wilf gagged and waved his arms frantically, then pulled out the dish and examined the turkey.

This didn't take long. It was quite a small turkey. Small and black and very crunchy. Wilf laid the dish on the hob and regarded it sadly.

"Sylvia's going to go spare," he said, resignedly.

It was at this point that the smoke alarm, finally registering the impromptu cremation in the kitchen, deigned to go off. Wilf and the Doctor ducked as it shrieked, but even beneath the strident wail, they both heard a far more ominous noise.

Neither of them moved. Two pairs of eyes swivelled to the microwave, where the Christmas pudding was bouncing around like a jolly brown pinball.

"What did you do?" whispered Wilf, hoarsely.

"I...may have messed things up a bit there, too," admitted the Doctor, just as wretchedly. The pudding started to pound against the door of the microwave, which shuddered on its hinges. The Doctor cleared his throat.

"Run?" he suggested.

Donna, who had thus far been so bored that she'd been giving serious thought to watching the Queen's speech, scrambled up as the Doctor came through the kitchen door like a gerbil on ephedrine, dragging Wilf behind him.

"Pudding in the hole!" he yelled.

The pair of them grabbed one of her arms apiece and ducked behind the sofa without further ado.

"What the bleedin' hell...?" Donna began, struggling to her feet and glaring over at the kitchen door. The Doctor bounced up, clamped a hand on the top of her head and pushed her down again. She shot him a furious glare, but he was counting under his breath.

There was a ping. This was followed by a brief silence. This was in turn followed by an even longer silence with subtle undertones of an extremely angry silence indeed, and this was followed by the kind of noise that can only be produced by a hand smacking a skull.

Donna popped up from behind the sofa, flushed and scowling, her hair awry. The Doctor surfaced, rubbing the back of his head, followed by Wilf, who was still looking extremely wary.

"Pudding's done," said Donna, and marched into the kitchen, slamming the door behind her. The Doctor was just letting out a large, shaky breath when there was a series of sounds.

The first was a soft, burbling squelch, which was followed by a high-pitched squeak. Hard on the heels of this there was a pattering noise, like rain, and this in turn was accompanied by an indignant and very definite scream. The Doctor turned to look at Wilf, who had crouched down behind the sofa again with his woolly hat pulled down over his ears.

The kitchen door creaked back and crashed against the sideboard like the crack of doom.

Donna staggered into the living room, wiping glutinous brown goo out of her eyes, although this was a rather ineffectual move since she was coated from head to toe in the stuff. She said something incomprehensible, and the Doctor cringed back.

There was another scream. The Doctor assumed at first that it came from Donna, but before he could react, Wilf started towards the stairs.

"That's Sylvia," he cried, grabbing the banister. His foot was on the first step, however, when he looked up, goggled and stopped dead.

There was a small blonde girl coming down the stairs, wrapped in a fluffy pink towel three sizes too large for her. She reached the bottom step and directed a poisonous glare at the Doctor.

"Twenty years younger?" she piped, furiously. "Look at me! I'm five years old!"

Wilf and Donna matched the accusing stare. The Doctor quailed, and tried to crawl up into his false beard.

"I put one tablespoon in, just like you said," snapped Sylvia, hysterically.

"Ah," said the Doctor, placing a hand to his forehead and chuckling nervously. "I'm sure I said 'teaspoon'. Didn't I say that? I'm sure I did. Didn't I? Donna? I said 'teaspoon', didn't I?"

There was no reply. The Doctor grinned weakly.

"Ho, ho, ho?" he said.