Doctor What and the Pot Noodles, by Terrance’s Dick.

“Sir! Sir!” The young UNIT soldier came crashing through the door.
Brigadier Lethbridge-Stewart looked up from some random paperwork on his big important desk and ruffled his otherwise-impeccable moustache. “What is it man?”
“Brigadier, sir, you asked to be told instantly the moment that anything strange happened,” the young soldier answered.
“Yes, I remember,” mused Lethbridge-Stewart, “Well, what of it?”
“Sir,” continued the soldier, “there’s…there’s…there’s Pot Noodles™ in the vending machine.”
The Brigadier had seen many things in his time but at this his blood ran cold. “Great Scott!” he cried, “Has anyone told The Doctor?”
“No sir,” said the soldier, “I thought it best to come straight to you.”
“Good man,” agreed the Brigadier, “but I expect he’ll want to know immediately. Come on.” Pausing only to grab his special Brigadier’s hat he swept out of the office and into Unit HQ.

Looking for all the world like an old police box, the familiar shape of the TARDIS stood in the corner of UNIT’s main Hangar One, where it had stood more or less ever since the Doctor’s enforced sojourn on Earth had begun. Stepping forward the Brigadier rapped smartly on the door.
It was answered by a complete stranger who for all the world appeared to be Peter Cushing. “Can I help you?” he asked the Brigadier.
“Who the heck are you, and where is the Doctor?” demanded Lethbridge-Stewart.
“He’s on holiday,” replied the Peter Cushing lookalike in a pleasant tone, “I’m a locum. My name is Doctor What.”
“What?”
“Yes,” beamed the Doctor, “That’s right.”
Brigadier Lethbridge-Stewart hadn’t risen through the ranks to command the finest UN-based anti-alien brigade in the BBC by being slow on the uptake. “Holiday, eh?”
“Yes. Skegness, I think. Or Weng Chiang’s house. One of the two. Now, did you want anything in particular? Lethbridge-Stewart, isn’t it?”
The Brigadier would have been pleased that his reputation preceeded him had he not caught this new Doctor peeking at a “Jane’s All The World’s Moustaches” behind the TARDIS door.
“That’s right,” he replied, “and I’m here on official business. Something strange has cropped up and we thought you should know about it. Something in this very base.”
“Hmm.” The Doctor frowned, “You’d better show me.” As he stepped out of the TARDIS the Brigadier could not help but notice that he was followed by what appeared to be a robotic duck.
“What is that?” he asked coldly.
“That is Quark,” replied the Doctor, “Is there a problem?”
The Brigadier frowned. “The other one usually has a dog.”
“I know. I wanted that but he was ahead of me in the line. I got old Quark here, and a jolly fine robotic duck he’s turned out to be I must say.”
The Brigadier mulled this over. “Quite,” he said, “Maybe I could borrow him someday?”
“I don’t know that I could spare all of him,” the Doctor frowned, “but I could always send you the bill.”
On this note it was decided that time was a-wasting and that the world in general would be better served if they went and had a look at the vending machine.

“Hmm,” said the Doctor in a tone that didn’t really inspire confidence, “yes, I see what you mean. Very mysterious.”
“It certainly is,” agreed the Brigadier, “Pot Noodles don’t belong in a vending machine! Good god, this isn’t Japan for heaven’s sake!”
There was a longish pause.
“Well?” asked the Brigadier.
“Well what?”
“What do you think it is?”
The Doctor looked a bit blank. “Oh,” he said, “Um, well, could be anything really.”
Behind his back the Brigadier felt his hands clench. “Would you care to take a guess anyway?” he said through gritted teeth.
The Doctor appeared to pick up on the way the wind was blowing. “Right,” he told the Brigadier, “Well, let’s see. It could be…I don’t know…the Zarbi?”
The Brigadiergot the distinct impression that this had just been pulled straight out of the Doctor’s arse.
“The Zarbi,” he said flatly.
“Yes,” replied the Doctor, beaming absently, “classic Zarbi behaviour, that.”
“The Zarbi,” repeated the Brigadier, “a peaceful insectoid race who live in the caves of their homeplanet Vortis, who are largely non-technological and have never developed space and/or time travel.”
“Yes.” The Doctor looked a bit uncomfortable, “they’re the ones.”
The Brigadier sighed. “Look, why don’t you pop back to the TARDIS and catch up on some reading,” he told the Doctor, “I think we’ll handle this one from here.”