A/N: For B5, this starts somewhere near the end of the first season, after episode 1.13 "Signs and Portents", but before "Chrysalis" (1.22). It may contain spoilers for the first four seasons though. For the Doctor, this is an alternate Doctor, in an alternate Universe, though he's similar enough to Tennant's Doctor.

BTW, I don't own B5, nor Doctor Who. If you assumed otherwise, I'm sorry for your sanity.

A strange, mechanical groaning sound reverberated in a dark recessed corner in an abandoned corridor in Brown sector. The sound repeated itself a number of times, in sync with a light flashing and a box-shaped blue shadow appearing and disappearing, until it finally materialized with a bump. The anachronistic blue box sat there silently, unseen by anyone, for a few minutes. Inside it, in a room that was way too big to fit within the volume occupied by the box, stood alone a tall man, dressed in some sort of blue suit. He examined the monitors and registers in a strange hexagonal console, with a baffled expression.

"Why, Old Girl? Why are we here?" but the box didn't respond. He tried pressing some buttons and activating a pair of levers, but the console just grumbled. "All right, all right. I'll have a look around." He disappeared through a doorway set in the walls, which led to the interior of the fantastic machine.

The box stood silently in the shadows for some ten minutes, unnoticed, until a door creaked open. The man slipped out, pulling up an incongruous brown overcoat, and walked down the corridor.

The man, who called himself the Doctor, wandered around the stalls on the Zocalo, one of the busiest areas of the Babylon space station. He looked around curiously, watching the buyers and merchants, smiling as he recognized each of the various species that visited the station. He was clearly more interested in the people than the various wares on sale, and walked slowly around. Twice, some shady individuals tried to tail him, thinking that perhaps he'd make for a good mark. Twice he turned and stared at them, and they quickly reevaluated their chances and dispersed. He was otherwise unnoticed, most others dismissing him after a quick glance, including the security guards, of whom there was a good number around. The man briefly observed them, his face twisted slightly in disgust at the uniforms.

The man's interest was briefly piqued when he saw a small group moving around, headed by a human in an EarthForce commander's uniform. That would be the station's commander, he guessed, one fellow named Sinclair. Another soldier, he thought, unimpressed. Their voices raised, discussing something in one of the stalls, and he glanced back in their direction, only to do a double-take. He raised his eyebrows, something only he could see grabbing his attention. He began to discreetly follow the group, noting with interest the other people that stopped to talk with Sinclair, and watching his words and actions. But he quickly found out that he hadn't quite managed to be discreet enough, as the station's security chief, one tough guy named Garibaldi, soon accosted him, with two other guards as backup.

"Who are you, and what do you want with the Commander?"

"Sorry, what do you mean, Chief?" was the man's unworried response. "I'm Doctor John Smith, see?" he said, presenting a worn leather wallet, holding an identicard to that name. "I'm just looking around."

"Just looking around, following the Commander for the last seven minutes, were you? Give me that," he said, taking his wallet to examine it. The handheld ID verifier confirmed the validity of the man's identity, but the security chief was nothing if not suspicious.

"And you are?" the man replied, unflustered, as Garibaldi unsuccessfully looked for the records of the man's arrival.

"I'm Security Chief Michael Garibaldi, and you're coming with us." It was quite possible that the man was another one of those Homeguard infiltrators, and Garibaldi wanted to question him.

Garibaldi was ready to subdue the man by force, half expecting him to resist arrest, but the man followed them docilely enough, smiling all the time, as if that was nothing more than a minor inconvenience.

The interrogation wasn't going very well. The man was irritatingly hard to pin down. No matter how hard Garibaldi tried to trap him with his questions, he smoothly deflected, never losing his cool.

"Who are you?" he tried again.

"I've told you, I'm the Doctor."

"Doctor who?"

"If you prefer."

"Your identicard is a very good forgery, but that's all it is. It says your name is John Smith, but we've checked back with Earth Central and there's no one with that name matching your face."

"Well, I'd be really surprised if there was."

"Look, mister, you may think it's a joke, but you're neck-deep in trouble. I already have you for falsified ID and illegal entry. Are you part of those Homeguard lunatics?"

"Homeguard? No no no. I just want to talk to your Commander Sinclair."

Garibaldi tried to lean harder, threatening him, but the man simply refused to answer any more, and asked again to talk to Commander Sinclair. Unwilling to resort to violence, Garibaldi stomped out of the interrogation room and ordered his men to take the prisoner to a cell.

A/N: Another story, another universe. I'm cleaning up my ideas chest, putting up whatever I have that is good enough. This one I quite like, though I'll probably never develop enough to do it justice. This is a story that came to me one day, while remembering the fantastic show that was Babylon 5, and wishing we had more like it. It assumes knowledge of the basic plot of the show, without which some things may not make some sense.

This story is set on a B5 Universe where there are Time Lords, similar to my To Boldly Go Universe (with B5 instead of Star Trek). This Doctor is an alternate of David Tennant's Doctor, and he's the tenth incarnation of the Time Lord (no War Doctor). There has never been a Last Great Time War (but there have been more than enough Time Wars) and there are no Daleks. As in TBG, the Doctor (and Time Lords in general) tend to stay away from the Milky Way (or Mutter's Spiral, both names for Earth's galaxy). Though here it's for different reasons than in TBG. Sort of. So the Doctor is familiar with human history, up to a point, but aside from a few preferred periods in Earth history, he tries to stay away. Until, of course, the TARDIS drops him there. Which also tend to occur from time to time. What will the Doctor do? This Doctor is (currently) companionless, and a bit more dangerous than the one we know and love.

For an excellent (and complete) B5xDW crossover story, see Shadow of the Doctor, by Kythrae (here on FFNet), where Four (oh I love Four) with Romana find themselves on B5 and accidentaly solve, sort of, a few bad things that happened (and nearly botch it all). There are many others, some of them shorts (some very good), others, unfortunately, incomplete. For one which I'd really love to see completed, see Angels of Babylon by Azaz3llo.