A/N: This is my first fanfic; I've been writing regular fiction for years, but had this story floating around in my head and wanted to give it a shot. Fanfic is turning out to be MUCH harder to write than I thought!

Advice, especially on staying in character, is welcome. I'm sure I'll end up stretching things with the medical stuff, but I'm doing my research and I'll try to be as realistic as possible.

Needless to say, all things NCIS are the property of people much cooler than me.

Anthony DiNozzo had little use for doctors. Aside from the occasional gunshot wound or touch of pneumonic plague, everything could pretty much be categorized as a sprain or a virus, and Tony didn't need a doctor to tell him that. "I'm just tired," he mumbled, peering at his reflection in the mirror above the sink. Pale, sweaty face, bloodshot eyes. "It's 3 AM. Nobody looks good at 3 AM." He leaned over and splashed cool water on his face, trying to stop shaking.

You have a fever, a voice whispered in the back of his mind. He ignored it, as he did every night. How long had this been going on? A few weeks, at least. He leaned against the sink, trying to remember the first night he'd woken, drenched in sweat and sick to his stomach, feeling like the room was spinning even with his eyes closed. How long had it been since he'd had a good night's sleep? At least...well, awhile, anyway. You're tired, he told himself firmly. We're working a tough case. Suck it up.

He left the bathroom on unsteady legs and looked at his bed. The sheets were tangled and still damp with sweat, and the thought of crawling back into it sent another wave of chills over his body. The couch would have to do.

It took him nearly an hour to get back to sleep, and by the time the alarm on his watch went off at 6 a.m., he was dead to the world.

"Tony! There you are!" McGee looked up as Tony made his way into the bullpen the next morning. "Where have you been?"

"Chill, Probie," Tony said, dumping his bag on his chair. "I know, I'm late, I'm sorry. Gibbs isn't here yet, is he? What's the big deal?"

"Gibbs isn't here because we were supposed to relieve him and Ziva an hour ago."

"Relieve...crap. Surveillance." Any hope Tony had of sneaking in unnoticed had just gone out the window. "I thought we weren't on until noon," he said, trying to sound genuinely confused. Better than saying Sorry, I woke up late and it took a half hour to talk myself off the couch. "Gibbs is probably pretty pissed, huh?"

"What do you think?" McGee shot him a look that he only risked when Tony had seriously screwed up. "Can we get going, please?"

Tony looked longingly at his comfy desk chair. Every muscle he had ached, and the fact that he would like nothing better then to pull a day of desk duty and paperwork made him wonder if his brain was screwed up right along with his body. "Sure," he sighed, picking his bag back up and digging out the keys. He'd go, but McGee could get them there. Maybe he could nap in the car. "Heads up!"

The keys flew towards McGee, and he turned just in time to grab them. "You want me to drive?"

"Is that a problem, Probie?"

"No, it's just...you hate when I drive."

"Well, now's your chance to show me how much you've improved." He managed an easy smile as he clapped McGee on the shoulder and strode past him to the elevator. "Are you coming?"

McGee's driving was maddeningly slow, but for once Tony was grateful for the snail's pace. He had actually managed to fall asleep for a few minutes before they pulled up behind a vacant apartment building. "Tony." McGee turned the car off and opened his door. "Come on." McGee was obviously still annoyed with him; he was already halfway up the stairs by the time Tony pulled himself out of the car, closing his eyes against a wave of dizziness. He waited a moment, steadying himself, before he hurried after McGee.

"It's about damn time," Gibbs barked as McGee entered the apartment, Tony on his heels.

"Sorry Boss," Tony said quickly before McGee could speak. "My fault. I overslept."

"Wild night, Tony?" Ziva murmured, not taking her eyes from the window that looked out across the street to the apartment that housed their target.

Tony forced a laugh. "Not exactly, David. Probably better than yours, though."

"Really, DiNozzo?" Gibbs turned, ready to give his senior field agent a thorough chewing out, but stopped when he caught sight of Tony's pale face. Instead, he bent and started gathering the papers spread out around him. "David, go and get the car while I brief these two. I'll be down in five." Ziva nodded, and McGee moved in to take her place at the window as she left.

"There's not much to tell you," Gibbs said, picking up his stack of paper. "Two phone calls, one to his mother and one to a Jan Cerny. Abby's running the name for us now, but there wasn't much we could tell from Andersen's side of the conversation. The calls are on the tape, though; McGee, give them a listen and run them through your system to see what you pick up."

"Got it, Boss," McGee said. "Tony, can you take watch?"

"Sure," Tony started over to the window, but Gibbs stopped him with a firm hand on his arm.

"Just a minute, DiNozzo. I want to talk to you. Outside."

Shit. He knew Gibbs wouldn't let him off so easily. He followed his boss out the door and into the rundown hallway. "I'm sorry -"

"Save it," Gibbs cut him off, but his voice was surprisingly gentle. "Are you OK?"

Taken aback, Tony almost blurted out No, but he caught himself. "I'm fine, Boss."

Gibbs' eyes narrowed. "You sure?"

"Yeah, I'm sure - why?"

"Because this is the third time you've been late in the past two weeks, and you look like you haven't slept in a month. You want to tell me what the hell's going on?"

"Nothing, Boss, honestly. Everything's fine. Better than fine, actually. If you know what I mean."

Despite Tony's best attempt at a lascivious grin, Gibbs gave him a look that clearly said I don't believe you. "Alright. Go relieve McGee, then. Call me if things start to move."

"Will do." Tony escaped back into the apartment before Gibbs could ask any more questions that he couldn't answer.

Surveillance, as usual, was a whole lot of hurry-up-and-wait. While McGee analyzed the phone calls, Tony took an extended turn watching out the window and tried not to fall asleep. Normally he would have joked with - well, tormented - McGee, but he didn't have the energy. The fact that McGee had a set of headphones glued to his ears made his silence much less conspicuous. Abby called in at one point to report that Jan Cerny was either a Czech arms dealer or a former Naval petty officer who currently managed a Waffle House in Orlando. All else being equal, the consensus was to go with arms dealer.

After about three hours, McGee pulled the headphones off and dropped them to the table, rubbing his eyes. "That's it."

"Anything?" Tony asked.

"I can't tell. The conversation itself was almost certainly in code, but we expected that. There were some background noises on Cerny's end that may have been a plane, but I couldn't get more detailed - the sound was too broken to get enough to identify the type, even when isolating the frequencies." He sat back, rubbing his eyes again. "Some of those frequencies were not meant to be heard for long periods of time. My head is killing me."

"Take an aspirin. You want a turn over here?"

"Sure. I made transcripts of the calls; maybe you can take a look, see if there's anything I missed."

After reading the transcripts twice, though, Tony wasn't any closer to making sense out of them than McGee. He tried to force himself to think. There was a piece missing somewhere...if he could just get his mind to focus...

Three weeks of surveillance on Andersen had led them down nothing but dead ends, and the entire team was growing frustrated. Everything was riding on a series of anonymous phone calls and three dead Marines. Each had worked at the armory at Quantico; each had access to some of the most advanced weaponry the U.S. military possessed; each had been murdered while on guard duty by a single gunshot wound to the back of the head after a convenient security camera "malfunction". The only connection between the three was Robert Andersen, who had been on duty on the other side of the base during each of the murders and, according to others on his shifts, had never left his post.

It should have been simple enough to bring Andersen in for questioning, but the phone calls added a new dimension. The oddest thing about the case was that nothing had actually been missing from the armory. Instead things had simply been moved - not trashed, but rearranged neatly in ways which the caller was able to accurately describe despite the information not having been released. The first call came immediately after the first murder, and simply said "Nothing is missing, but do not assume nothing has been taken." Andersen's name came after the second murder, and the most recent call informed them that Andersen would be meeting with his contact "soon." Nothing about who the contact was, why they were meeting, or what was to take place. Tony was starting to feel like a puppet; they were being fed bits of information by someone who was clearly involved in some manner and seemed to want nothing but to watch them all jump. Yet the danger inherent in the repeated security breaches was too high to risk ignoring him.

Tony sighed. "Take a break, McGee. I'm not getting anywhere over here. Find some lunch or something."

"I can wait, Tony, if you want to go."

"Nah, go ahead. I haven't looked out the window in almost twenty minutes. I'm starting to forget the pattern on the drapes in 2B."

As annoyed as he still was with Tony, McGee couldn't help smiling. "I'll bring something back. What do you want?"

The thought of food brought back the nausea that had been lingering all morning. "Nothing," he said shortly.

"Nothing?"

"No, I'm good. Take your time."

"Tony, you haven't eaten all morning. By now you'd usually be halfway through a pizza."

"I had a big breakfast, McGee. Just go, OK? I'll get something later."

Tony started to take McGee's chair, but a slight movement at the corner of his eye drew his attention. "Hang on." He picked up the binoculars for a closer look, and saw the draperies in Andersen's apartment move again, as if blown by a puff of air. "That could have been a door closing." McGee joined him at the window, and a moment later the front door to the apartment building opened and a nondescript man wearing a stocking cap came out. "That's him," Tony called, already halfway to the door. "Let's go, McGee."

The two men headed to their preassigned posts; Tony on foot, blending in as well as possible in the sparse population on the sidewalk, and McGee in the car around the corner, ready to move in. Tony kept his phone to his ear, updating McGee as he walked; as long as he didn't speak too loudly, the phone was an excellent aid in appearing oblivious to his surroundings.

"He's heading south, about two blocks ahead of me." Tony murmured, then, more loudly, "You're shitting me!"

"I'm shitting you about what?" McGee said, sounding confused, and Tony stifled a sigh. McGee was great with computers, but human interaction sure threw him for a loop sometimes.

"C'mon," he said. "You know what I'm talking about!"

"No, I don't - oh." McGee sounded abashed. "You're blending."

"Now you're getting it!" Tony said, then laughed as though McGee had said something amusing.

"Thanks for the lesson. Where is he."

"Still two blocks up."

"Does he seem suspicious? Looking over his shoulder or anything?"

"A couple of times. Pretty quiet, though." He paused as Andersen glanced over his shoulder again. Tony couldn't tell if Andersen saw him or if he was just spooked, but suddenly the man broke into a dead run. Tony took off after him. "He's running - pull out at 7th, try to cut him off."

A surge of adrenaline overrode the weariness in Tony's limbs, but it didn't last long. He only made it a couple of blocks before his chest began to tighten. Keep going! Half a block more. One block. One more...

Finally Tony was forced to stop. He leaned over, trying desperately to catch his breath. "Is he still running?" McGee said in his ear, but Tony couldn't answer. All his energy was focused on a futile effort to get air into his lungs. Black spots played at the edges of his field of vision, and he fell to his knees as his legs refused to support him anymore. "Tony? Tony!" McGee's voice seemed a long way off.

The phone tumbled from his hand, and he heard car wheels squealing around the corner as darkness closed in.