[Doctor who is owned by the BBC and Discworld is owned by Terry Pratchett]
Slowly and steadily the Doctor's ancient and impossible craft heaved itself through the vortex like a tug boat in an impossibly stormy sea. The engines roared their ancient song as the Doctor himself stood before the console slamming levers and pumps confidently into place. His leather jacket swayed wildly as he hopped from panel to panel in time with the the rising and falling of the time rotor. He slid some important dial into position and the g-forces acting on him increased slightly,suggesting that the TARDIS had changed gear.
There was a jolt that the Doctor was not expecting,and another,and another. Each time he was almost knocked to the floor by the sudden unexplained juddering,eventually he was sprawled over the console clinging for dear life as he waited for the gut wrenching turbulence to pass. With a sound like the mother of all computers powering down the console room was plunged into darkness and everything went deathly still.
The doctor got to his feet and pricked his ears against the silence,he heard nothing. He groped at the console looking for the light switch but stopped in mid grope as a new resounding sound filled the room. It was a very familiar sound,the groaning and wheezing of engines,but not his own. They sounded for all the world like TARDIS engines yet somehow otherworldly.
The noise died and for some inexplicable reason the lights snapped back on with a hum. The doctor looked around for the source of the noise and was immediately taken aback when he saw a wooden box sitting a few feet away as if it had always been there. It was about the size of a phone booth and a small lantern was set on its top. in a state of utter confusion the doctor crossed over to it and found one side of it to have doors. This side of the box was covered in writing,across the top in some strange language that the doctor had never read before was carved the message:
ANKH MORPORK CITY WATCH
"Where have I heard that before?" thought the doctor.
Scanning his eyes over the rest of the doors he noticed a small inset panel with a longer message in the same alien tongue. This one read:
WATCH CLACKS STATION
FREE FOR USE OF PUBLIC
WATCHMEN AND CARTS RESPOND TO ALL CALLS
The doctor gave a long 'Hmm' as he ran his fingers over the wooden surface of the sign,drawing on what he already knew from encounters with similar boxes,including his own. He grabbed at the inset panel and as he expected it swung open to reveal a little cupboard.
He had been expecting some advanced communication apparatus to be inside but was instead greeted by two wooden paddles that looked like malnourished ping pong bats. He reached inside and removed them from their stand,he turned them over in his hands for a while then replaced them. "Semaphore paddles,"he concluded.
He was just about to run his sonic over the strange parody of a police box when a door swung open and a bearded head poked out.
"Errm,hello?"said the head tentatively from beneath its rather sorry looking pointy hat. A word was scrawled across it which was translated right down to the misspelling by the TARDIS's clever circuitry.
"Hello!" the Doctor replied in his usual gleeful fashion, "I'm the Doctor and I can't help noticing you've landed inside my ship."
The head looked confused and vanished back into the recesses of the box,the doctor was certain he'd seen the strange man dressed as a wizard somewhere before.
From inside the box the doctor heard a rapid conversation and something which kept going 'Ook'. The head re-emerged and addressed the Doctor once more, "Ship?" it asked, "Have we come down somewhere in the circle sea?"
"I'm afraid not,"the doctor said, "This is a space-time ship like yours,a lot like yours by the looks of things."
"Impossible" snapped the man who the Doctor later found out was called Rincewind, "This is the first BARDIS ever built. I didn't refuse to volunteer for this bloody HEM project only to find that some other bugger has already built one. Why do I have to boldly go to absolutely certain death again when there was already some other bugger doing it for me?"
"BARDIS?"said the doctor in complete confusion, "May I ask what that stands for?"
"Why, Books and Relevant Dimensional Insertion Spell of course,"explained the Wizzard, "But you knew that already since you've obviously stolen our bloody plans."
Another bout of angry ooks erupted from inside the Watch box, "Hold your horses I'm dealing with it!" Rincewind shouted back to the mysterious ooker before turning back to the Doctor, "Look..."he sighed, "He says there's very little thaumic energy in this part of the multiverse so if we don't go back into L-space now we won't have enough thaums in the tanks to make it home."
"L-space?"mused the doctor to himself, "Is that anything like E-space?"
Another couple of irate ooks echoed from inside the box and Rincewind sighed again. After a while he said in a more polite tone, "Sorry,we really must go,nice to meet you Doctor."
With that Rincewind slammed the door of the box shut in the Doctor's face as a humming emanated from inside.
"Hold up I've got a few more questions!"the Doctor called as if the thing was driving away rather than standing still. He held his screwdriver up to the door of the watchbox and it swung open apologetically,just enough to allow him to slip inside and close the door.
He made it inside just in time,no sooner had the doors closed behind him the box vanished from the TARDIS console room with a flickering octarine glow and a faint smell of books...