Disclaimer: I don't own NCIS or Doctor Who, unfortunately...

A/N: Set after series 4 of Doctor Who and sometime in Season 5 of NCIS.

Prologue

"We'd make an awesome superhero team." Special Agent Anthony DiNozzo grinned, leaning his head back against his hands as he absent-mindedly tipped his chair back.

"How'd you figure that out, then?" Timothy McGee glanced at his co-worker over the top of his book.

"Well, we have Ziva… Ninjawoman!"

"I am not a ninja, Tony," the Mossad agent sighed.

Tony continued as if he hadn't heard her. "Probieman, the computer geek. And, of course, me, the handsome one that always ends up saving the day. Just haven't thought of a heroic enough name for me yet."

"So, what about Gibbs?" McGee couldn't help it, he was curious.

"What about Gibbs?" The person in question strode down the steps, holding a large polystyrene Caf-Pow! cup, and walked straight past the three of them towards the elevator. "Coming?"

"Uh, nothing, boss." McGee jumped to his feet, noticing Tony and Ziva doing the exact same. Hurriedly, he shoved his book into the drawer in his desk and picked up his equipment before following his boss and co-workers into the elevator.

"Where are we going, boss?" Tony enquired.

"You'll see," was all Gibbs gave as an answer, leaving the elevator in silence as it descended down towards the ground floor. He was still silent as he led Tony, Ziva and McGee out of the building and into the bright sunlight.

He didn't need to speak. For, lying there on the slightly-pink, bricked walkway in front of the Naval Criminal Investigative Service Headquarters was a body, surrounded by officers.

"Well, someone sure wanted our attention," Tony murmured.

"But for what purpose?" a voice behind them spoke. "A rather morbid way of doing so, don't you think?"

"And how did she get here?" McGee followed on from the medical examiner's question.

"As far as we can tell, she just appeared here." The oldest and seemingly highest ranked of the officers shrugged as the rest left the scene. "No ID, no witnesses, no nothing."

"'No nothing' implies the presence of something." Dr Donald 'Ducky' Mallard knelt down by the body, continuing a minute or so later with, "Body temperature is ninety-five degrees, rigor mortis is barely setting in. This woman hasn't been dead long. An hour or so, perhaps."

"To manage to plant her here would have needed planning," Ziva noted, snapping a picture of the corpse's tightly fisted hand, in which was a scrunched up piece of paper.

"Cause of death?"

"No obvious signs of trauma, but something appears to have burned through her top, here." Ducky gestured at the corpse. "For anything more definite, you'll have to wait until we get her inside."

"Ziva, DiNozzo, photos. McGee, check the security tapes and find out who the hell she is!" Gibbs ordered, striding back towards the building as his team unanimously cried in reply, "On it, boss!"

"Abby ran our Jane Doe through CODIS. No match. No-one with her description has been reported missing recently, either." Tony stopped his pacing and stood directly in front of the plasma screen to stare at the crime scene photo displayed.

"There's nothing on the security tapes, boss. They've been wiped. Completely. Whoever did this knew what they were doing. I'm trying to find the hacker now…" McGee stared helplessly at his keyboard.

"And, the piece of paper we found in her hand seems to be in some sort of code." Ziva sighed.

"So, basically, we've got nothing," Gibbs summed up the team's findings, reaching for his phone as it began to ring. "Yeah, Duck?"

"You may want to see this, Jethro."

Without answering, Gibbs shut the phone with a snap, ending the short call, before heading off towards the autopsy room.

"Have you ever played laser tag, Doctor?" Jimmy Palmer asked as he examined the odd burn mark on the corpse.

"Ah, no, Mr Palmer. Not really my type of game nowadays. I don't believe that it was her type of game either, was it, my dear?" he addressed the body.

"Cricket," Gibbs answered Palmer's next question before he had time to speak it. "What killed her, Duck?"

"See this burn mark, here? This poor woman was hit with a beam of intense heat. Once it managed to burn through her skin, it boiled her insides instantaneously. My guess would be some sort of laser. That makes my earlier estimate of time of death void, I'm afraid. However," Ducky picked up a jar filled with what appeared to be purple sludge, "I found this in the remains of what was probably her stomach. I've sent a sample to Abigail for testing, but it's nothing I've seen before. I only hope she can give you more than I can."

"I know your game. You're trying to trick me." Abby glared at the computer screen. "No machine can fool me! I'll find your secrets, you can bet on it!"

"Any luck, Abs?"

"Oh! Gibbs!" Abby spun around and gave Gibbs a quick hug before relieving him of the Caf-Pow! in his hand. Three noisy slurps later, she placed the cup on the desk next to her and returned to glaring at the screen. "No. I analysed that purple sludge stuff that Ducky sent me and I didn't recognise the chemical composition at all. I'm running it through the computer now."

Right on cue, the screen changed from showing a list of scrolling chemical symbols to two flashing, bold words. 'Compound Unknown.'

"Ha! You think you've got the better of me…" Abby growled, reaching for the Caf-Pow! and tapping a few keys on her keyboard. "Most of the compound doesn't even seem to be in the system. That's odd. The only thing it can recognise is… Water."

"Water?"

"I'll try running this manually. It may take a while…" Abby trailed off as Gibbs produced another Caf-Pow! from behind his back. "A short while," she quickly corrected herself.

"Got anything?"

"Nothing. We have nothing," Tony replied.

"Why would someone get our attention and then not give us any clue?" Ziva mused.

"Well, there's the note," McGee pondered, tapping his keyboard to bring a scan of the note up on the plasma screen.

Ziva sighed. "It's not in any known language or code and we cannot translate it."

"Ohh… That may be a job for me."

In unison, Gibbs, Tony, Ziva and McGee spun around to see the newcomer who had spoken. He was tall, with hair that seemed to have a mind of its own, and was wearing a brown pinstripe suit. He had his hands shoved in his trouser pockets and didn't at all seem perturbed about standing in the middle of the squad room without a visitor's pass hanging around his neck.

Within a manner of seconds, four guns were pointing at him.

"Well, that's not a very nice welcome."

"How did you get in here?" Gibbs barked.

The man made a vague gesture towards the elevator. "Walked in."

"That is impossible." Ziva narrowed her eyes. "You would have been stopped by security."

Four safety catches were clicked off as the man reached into his pocket and pulled out a battered brown wallet. "Look," he said, showing the paper inside to them.

"You're from the British Embassy?" Tony lowered his gun. "You still should have got a pass."

"That paper is blank," Ziva argued.

Tony glanced at her, puzzled. "Ziva, it clearly isn't."

"No. You just want it to not be blank. You expect it to not be. It is all in the mind." If she had not have been holding her gun steady, Ziva would have tapped the side of her head to emphasize her words.

McGee was crossing and uncrossing his eyes and squinting at the paper. "If I do this, it has writing on it. If I do this, it's blank."

"Oh, come on! I can't really be imagining words!" Tony looked at Gibbs for support.

"She's right, DiNozzo. It's blank."

"Ah, well. Worth a try." The man returned the wallet to his pocket. "This is NCIS, isn't it? I'm looking for Doctor Donald Mallard."

By now, officers had gathered around the squad room, sealing off any means of escape for the man. Gibbs gestured at two of them and they grabbed his arms tightly. Gibbs opened his mouth to speak, but was cut off by a voice from the top of the stairs.

"Take him to interrogation," Director Jenny Shepard ordered. "Jethro, my office. Now."

"What was that about?" Jenny watched Gibbs closely as he closed the door behind him and walked over to stand right in front of her desk.

"I have no idea," Gibbs confessed.

Jenny sighed, knowing that he wouldn't admit that lightly. "I've sent Ziva to interrogate him. Any leads on this Jane Doe?"

"Nothing."

"I have a funny feeling that this is a warning, Jethro." Jenny reached over to press the speaker button as the phone on the desk buzzed. "Yes?"

"Agent DiNozzo, Director," the woman on the other end said.

"Let him in," Jenny replied, pushing a stack of papers to the side of her desk.

"Uh, hey, boss, Director." Tony closed the door behind him. "Ziva's getting nothing. This guy just wants to talk to Ducky. Says he knows something about the case."

"Then get Doctor Mallard in there. I need something definite on this before I talk to SecNav."

"Ducky!"

"Back again so soon, Jethro?" Ducky turned away from the body drawer and towards the man who had just entered the room.

"You've got a visitor."

"A visitor?" Ducky sounded surprised.

"Yup. Says he knows you. More importantly, says he knows something about her." Gibbs gestured towards the drawer. "Ziva's with him, but he's not saying anything."

"I would not say that!" Ziva marched into the room, glaring at everything and nothing. "I have never heard anyone talk so much and yet say so little!"

"Well then, I should not be so discourteous as to leave this visitor waiting."