This is a kind of multi chapter case file I've decided to try and write. It's set in a season 11 world where Ziva was still at NCIS. The plot is a bit...out there and it may contain some cliches, but it's my first attempt at a story of any real length so hopefully you can cut me some slack. I was gonna try to complete it so I could post it all at once, but decided I might lose motivation that way. So I've posted the first chapter in the (probably optimistic) hope that you guys will show interest in the plot. If it's just a load of rubbish, please don't hold back on the criticism. There's no point in me finishing a story no one's enjoying. Hope you are entertained.

Monday did not always represent the start of the working week for Team Gibbs. In fact, the hard working, coffee fueled agents often found themselves in a seemingly endless loop of consecutive working days without a break. Sometimes they even needed a reminder, from people with ordinary lives, what day it actually was as their minds got as disjointed as their sleeping patterns. Their boss never had that problem, of course. Gibbs would probably be confused after a full night's sleep but never had an issue with his usually non-existent ones. The man was simply a machine. This particular Monday was a rare and precious occasion then, because the NCIS family actually spent the entire preceding weekend off. They weren't once interrupted by the call of duty.

Although, ironically, Tony DiNozzo suspected that a certain McGamer had spent the entire weekend playing a video game similar to 'Call of Duty'. The tech whizz seemed to still find the activity appealing, even at his ever increasing age. The virtual world enthusiast was nowhere to be seen as Tony made his way past his fresh faced Israeli-American partner and slumped into his chair with a typically exaggerated groan. God, this was not a good way to start the week. He might not get the chance to catch up on his sleep any time soon, either. Not as a member of the MCRT. Lord only knew what lay ahead.

Ziva didn't fail to notice the apparent suffering of the senior field agent, or the fact that he hadn't said a single word of greeting since arriving. She always figured he would never get used to being up at 7am, no matter how much practice he got at doing it.

''You seem tired, Tony.'' She stated, without even glancing at the exhausted agent in question.

As she kept her attention on her computer monitor, she just about heard a grunt of confirmation from her partner. Clearly using any actual words was beyond his ability. His already closed eyes were a physical indication of just how tired he really was. She only ever saw him in this particular state when he'd experienced a night of heavy drinking the day before. That usually involved hitting the town with his friends. She knew he rarely did that these days, and never on a Sunday night. As far as she was aware, he had brought a stop to the self-flagellant alcohol poisoning he brought upon himself after a certain trip to LA many years ago, so that couldn't be behind his obvious struggle. She examined him more closely for the first time that morning. There were no signs of pain marring his features, so it was not a hangover.

''Late night?'' She asked innocently. The curly haired minx may have failed to hide the concern lacing her tone, however.

Tony opened his eyes and found himself looking into the deep, brown ones of his gorgeous partner. Holding her gaze always made it hard to lie convincingly. He decided it wasn't worth the effort of even trying to make up a less mysterious reason as to why he was so sleep deprived that morning. The real reason was so frustratingly unknown to him, in fact, that he wasn't sure how to put it into words. His trail of thoughts ended, though, as he starkly realized he'd been staring into Ziva's enchanting orbs for longer than appropriate without actually speaking.

''No.'' He eventually answered with a heavy sigh. ''Just a long one.'' His following yawn reinforced the deliberately vague explanation he'd offered.

What on earth did he mean by that? Ziva assumed, by his lack of a proud smile, that he wasn't referring to a sexual conquest. Or perhaps she just hoped he wasn't. She didn't have time to inquire further, though, before Tony voiced a question of his own.

''Where's McGeek?'' He asked, before closing his eyes once again as he leaned back and used his hands to support the weight of his head. ''I never get in before him. He sick or something?''

Ziva's eyebrows furrowed in confusion. ''How would I know?'' She answered as if he was being completely absurd.

''I thought you magically teleported here as soon as the sun rises. Do you not pick up on these things?'' He shot back. Apparently his exhaustion hadn't suppressed his usual wit.

''I do not know everything that is going on just because I arrive to work first, Tony.'' She explained as if he was a petulant toddler.

That earned her another grunt. Clearly he was unwilling to argue with her any further on the subject. Now she was really starting to worry. Tony always argued back. Even if he was aware he was losing a debate, he would stretch it out over a potentially infinite amount of time. He wasn't just sleep deprived, he was rattled. Whatever had kept him up all night had clearly got under his skin. This was most unusual. It appeared Ziva's first case of the week had just been opened: The case of what the hell was wrong with Tony?

Her contemplative thinking had her in such a daze, that she failed to notice McGee enter the room and drop into his own chair with an uncharacteristic lack of grace. When she eventually looked him, and noticed his droopy eyes and gaping mouth, she couldn't help but see a similarity between his appearance and Tony's. In fact, he hadn't greeted anyone either. He was always the polite one of the group. Now Ziva's curiosity levels had truly risen to dizzy heights. This case was really developing.

''McGee?'' She said, catching his attention. ''Do not tell me I am the only one who rested during our weekend off. You look awful.'' She glanced back at Tony. ''Both of you do.''

McGee had his head in his hands by the end of her statement. His grunt arrived in unison with another one from DiNozzo. Ziva jumped to the conclusion that he was no more inclined to react vocally than his male colleague was. There was no such thing as a coincidence, or at least that was what their boss had drilled them into believing over the years, so there must have been a connection. This problem both her teammates apparently shared must have meant she missed out on something very time consuming over their little break.

''Okay,'' She began in a stern tone. ''One of you will tell me what happened last night or I will start throwing things. Very sharp things.''

This seemed to do the trick for McGee who looked up from is desk with a worried expression. Tony didn't seem too unsettled by her threat, however. He simply let out a long groan suggesting he didn't welcome the intrusion of his partner's voice.

''If one of these sharp things is a syringe filled with a sedative…'' He began, before another yawn interrupted his remark. ''…then fire away, GI Jane.''

Ziva rolled her eyes at the typical manner in which her partner displayed his attitude. She turned back to McGee, hoping she'd have better luck with the younger man. He was also mid-yawn by the time he met the questioning look in her eyes. She knew he was about to cave as soon as he shrugged his shoulders with a resigned look on his face.

''Look…'' He started in a frustrated tone. ''It's kind of hard to explain. I don't know about Tony here, but I didn't catch a wink of sleep last night.''

That information caught Tony's attention. He opened his eyes as his head snapped round to his male companion. ''That's a hell of coinky-dink, McLullaby. I had the same problem.''

''There is no such thing as a coincidence, DiNozzo.'' Their master and chief's voice met their ears as he glided into the bullpen. He was wearing his trademark Gibbs sports jacket and had his favorite caffeine-filled brew in his grasp, but stopped in his tracks after immediately picking up on the fact that the two other men in the room hadn't even moved a muscle since his arrival. He turned to Ziva with his own version of a confused frown.

''What the hell is wrong with these two?'' He asked gruffly, gesturing in their general direction with a flick of his head.

She wished she had an answer for him. ''You know as much as I do, Gibbs.''

Her honest reply was met with a simple 'huh' from the silver haired team leader. He simply turned back to his exhausted agents with an expectant expression ''Whenever you two wanna join us, just let me know.''

His sarcastic remark kicked the two men into action. McGee jumped up with a 'sorry boss' and went to grab his gear, and Tony sat up straight and put on is best alert face. ''Dead marine, boss?'' The Italian asked.

''Nope.''

''Dead petty officer?''

''No, DiNozzo.''

''Dead…anybody?''

''Nobody's dead.''

A confused frown slowly spread over Tony's face as his trail of guessing seemed to come to an end. ''Okay, this game's not fun anymore.'' He surrendered. ''Have we got a case of any description, boss?''

The boss in question gave his senior field a steely glare before simply turning away and sitting down behind his desk. At that, Tony's confusion seemed to become even more defined in his expression. Clearly his mind was working at a much slower pace than usual. He and Gibbs usually shared the same wavelength, but on this particular morning the telepathy just didn't seem to exist between the two long-time team mates. Gibbs pointed at the pile of folders on Tony's desk without even looking up, or without further elaboration. The younger agent examined them, and his reaction suggested he hadn't even been aware of their presence until this point.

''Cold case files?'' He asked with a wince.

Gibbs simply hummed in confirmation. McGee sat back down as Tony retrieved the first folder from the alarmingly high stack and flicked through the pages with a look of disgust. Ziva watched his unenthusiastic reaction with a small smile of amusement. He hated digitally converting case files on a good day. There was no way his current state of mind suited such an activity. He must have sensed her enjoyment of his impending suffering, though, because he looked up at her with narrowed eyes and a small frown.

''This what you've been doing all morning?'' He asked with a furrowed brow.

She chuckled before giving her partner the fake reassurance he didn't need. ''Oh yes, and I am having the time of my life.'' Her sarcastic remark brought another wince to his face. ''Do not worry, though. It only takes about half an hour per page. And that's only if your brain has been well rested.''

That news seemed to deflate whatever hopes Tony had of getting through this day with his sanity intact. His hand met his forehead as he face-palmed himself in complete surrender. ''Wonderful.'' He returned in an equally sarcastic tone.

''You got an issue, DiNozzo?'' Gibbs asked, this time he did decide to look up at his oldest agent with a raised eyebrow.

''No, boss.'' The DiNozzo in question replied, with as much enthusiasm as he could muster. ''I can think of nothing more exciting. I'm actually glad you wanted us to-''

''Shut up, Tony.'' McGee's sharp voice interrupted his fellow agent's rambling.

It was only the second time he'd spoken since Gibbs had entered the scene, but it almost sounded as though he was talking in his sleep. His eyes were closed again as he apparently couldn't find the energy to work, even in front of his boss. That didn't seem to bother said boss though, as something had seemingly caught his attention in vicinity of MTAC. Upon seeing her leader's steely gaze being held firmly in place in that direction, Ziva glanced up to see Vance standing with his usual authoritative posture, eyes firmly locked with the icy blues ones of the ex-marine. He stood at the top of the stairs and, after a few moments, he simply turned back towards his office and disappeared. These days, she was aware of the fact that was his way of summoning the team leader to his directorial lair. And sure enough, Gibbs got back to his feet and made his way towards the foot of the stairwell without a single word.

''I don't exactly see you springing into action with your case files, probie.'' Tony eventually reacted to his co-worker's barked order, about a minute after he received it. ''I don't think you're entitled to tell me what to do.''

''I'm just giving the office monkey a head start.'' McGee shot back after another heavy yawn.

''Monkey? That's a mean thing to say about Ziva.''

Ziva actually smirked at the typical DiNozzo quick-thinking, though she was growing increasingly irritated by the petty squabbling between the two grown men.

''Oh please.'' McGee admonished. ''Ziva's actually got some grace. Some appreciation for peace and quiet. Unlike her overgrown baby of a partner.''

Tony's jaw dropped. ''Overgrown baby?'' He repeated in disbelief. ''You're really saying that about a guy who gets more sex in a year than you do in a lifetime?''

''I rest my case.'' The younger agent stated with a raised hand.

That earned a scoff from his senior field agent. ''Maybe you should spend more time resting cases and less time resting those legs, McPudgy.'' He muttered under his breath.

''What?!'' McGee suddenly yelled. His angry look suggested he hadn't quite caught his colleague's comment.

''I said…'' Tony started in a much louder voice. ''Maybe you should spend-''

''Oh would you two please stop it!'' Ziva jumped in. Early morning bickering was not something she was willing to tolerate. ''Just because you are both miserable doesn't mean I have to be. I was actually in a good mood today.''

Her little motherly outburst seemed to have its desired effect. Both her friends visibly calmed as they slumped further back in their chairs with childish frowns. She was actually quite proud of herself. It was a rare occasion when she managed to end one of their juvenile arguments. McGee had always been polite enough to shut his mouth when she asked, but Tony never did. At least, not without the need for physical violence anyway. Now she officially granted herself permission to be concerned. Her partner even started working on his first cold case file. Was this really happening? Who was this person?

''Why were you in such a good mood this morning, Miss David?'' He voiced in a teasing tone. That was more like it. ''Did you have a particularly...pleasant weekend?''

He was even smiling now. She would normally have reflected his teasing straight back to him, but she was actually too relieved that Tony was still treating her like he normally would. If he kept genuinely listening to her demands for silence, she would keep worrying about his mental health. This didn't stop her being aware, however, that he was using his special DiNozzo language to imply that she had spent a 'pleasurable' weekend in the company of a man. This was, of course, not true. She had used their time off to indulge in some much needed rest and relaxation. It was pleasurable, but not in the way he was probably imagining. These days, she actively tried to avoid the whole jealousy theme these conversations often ended up adopting. Especially after what happened a fortnight ago. Therefore honesty was always the best policy in this situation.

''It was nice, yes.'' She replied, addressing the appearance of the question but not the underlying message. ''I got a lot of things done, put my feet up and allowed myself plenty of time to sleep. I am guessing you cannot say the same about yours?'' She asked, raising her eyebrows expectantly.

He tilted his head in consideration as he presumably recollected the events of his weekend. ''Yeah, actually I can.'' He returned, but with no hint of fight in his voice. ''At least for most of it, anyway. The whole sleep thing went kinda AWOL last night, though.'' His recollection brought another frustrated frown to his face.

''I know what you mean.'' McGee spoke up again, this time actually agreeing with other agent. ''I went to bed last night and just couldn't get to sleep. I just kept tossing and turning. My brain just wouldn't switch off. Didn't drift off even once before sunrise.''

Tony furrowed his brow and his eyes went distant after hearing the younger agent's description of the previous evening. Ziva recognized the particular look on his face in that moment. He was either freaked out by something, or genuinely concerned about his co-worker. She guessed, because it was Tony, that any concern he felt would most likely be for himself at this point. Nothing McGee described sounded like a long term issue, so what had DiNozzo so perplexed? She didn't have to wait too long to find out.

''That's weird.'' He started in a completely serious tone. ''I had the exact same experience. Like, you felt really tired but you just couldn't fall asleep? No matter how comfortable you were?''

''Yeah.'' McGee stretched out his answer as he also started to look a bit suspicious of the fact he and his colleague shared the same insomnia-related problem.

Ziva, in truth, was a bit skeptical herself. But she wasn't going to start freaking out Abby-style any time soon. ''Perhaps you are both just lonely.'' She stated with a shrug of the shoulders. ''Maybe you just need someone to comfort you at night.''

This returned the teasing smirk to Tony's face. ''Are you making an offer there, sweetcheeks?'' He asked in a slightly more lifeless tone than she was used to.

Ziva simply rolled her eyes, as he would expect of her, and returned her attention back to her work. She wanted to give the impression that his question was not worthy of being dignified with an answer. The truth was, however, that she couldn't picture herself and Tony sharing a bed without feeling a sad ache in her chest. They had done just that- shared a bed- as they finally gave in to their urges and slept together at her apartment nearly two weeks prior. She wasn't sure what it actually meant, but decided to go with whatever flow Tony wanted to. He hadn't even brought it up since the morning after their rule breaking activities, so she decided not to either. She could just about convince herself to ignore the way her heart squeezed every time she thought about it. Tony must have sensed her almost nervous energy, though, because the next time she chanced a look at him the smile had dropped from his face as he gave her an apologetic wince. Thankfully their long time colleague was either too blissfully ignorant, or just too tired, to pick up on the tension erupting on the other side of the bullpen.

McGee's trepidation about the earlier topic seemed to be continuing. ''I don't know,'' He started in a suitably unsure tone. ''isn't it a bit strange that both of us went through the same thing last night without really having a reason for it?''

It was very strange. But Tony couldn't help but feel like there was a reason behind it. Maybe Ziva was right, maybe he was just lonely. The warmth and touch of his partner was something he yearned for every evening since they'd strayed over the line of professionalism all those nights ago. He may not have consumed much of the Ziva David drug, but he was silently suffering the withdrawal symptoms of it. He knew that one simple, honest conversation could help clear this up, but was terrified of what consequences such a talk might bring. They could either bring happiness or heartbreak. He wasn't sure if he could deal with the latter, and knew the former would take hard work to achieve, so therefore decided to just survive with the hollow feeling he had in his chest on a day to day basis. Or could the hollow feeling already be considered as heartbreak? He wasn't going to think about the answer to that until he'd had some sleep.

…

''You wanted to see me, Leon?''

Gibbs entered the office to see the NCIS director standing by the window, looking out over the Potomac River. The usual poker face was in place, but the ex-marine could just feel the stressful tension in the room. The fact that Vance hadn't even looked at him since his arrival spoke volumes. Eventually the director let out a long sigh before turning around and approaching his desk.

''That terrorist cell you brought down last week.'' He said after a few more silent seconds. This was his way of half-asking if Gibbs could remember the cell in question. Of course he could. They nearly managed to launch a chemical weapons attack on a carrier. That was, of course, before his team stopped them.

''Kinda hard to forget.'' He responded, confirming his recollection of their foes.

''Turns out they were just a spoke on a much larger wheel. I just received this anonymous message a few minutes ago.''

Vance then hit the desk phone located by his computer, and the two men attentively listened to the message in question. The voice that met their ears was not a human one, but instead sounded deep, morphed and almost robotic.

''NCIS. We have not had the pleasure of meeting in person, but hopefully that will change soon. Agent Gibbs' team may have temporarily neutralized our operations in DC, but I strongly advise that you do not get comfortable. In fact, we've managed to put together a new formula to help you with that. Have a nice week.''

The message ended. Gibbs met Vance's gaze as they both calmly dreaded what the unknown threat could have possibly meant by that. He guessed that a 'new formula' meant a new lethal gas, but that was literally the only information provided that they could work with. Other than that, all they knew was that this unfamiliar enemy had identified him and, presumably, the rest of his team. That only ever spelled bad news.

''Trace?'' He asked, without having to explain further.

''Get McGee on it.'' The director ordered, without missing a beat. ''But something tells me this guy's covered his ass in that respect.''

Oh yeah. This guy was clearly not messing around, and clearly knew how to make the most of technology. That much was clear. But if anybody could crack the undoubtedly existent codes, his tech-savvy young special agent could. Before he could express any further opinions, however, Vance's phone started ringing. They were both seemingly thinking the same thing. Gibbs nodded once to confirm that he was on the same wavelength, before the director answered and put it on loud speaker. He had barely had time to say 'Hello', before the same deep voice from the earlier message blared out of the speaker once again.

''I assume you have now summoned Agent Gibbs?''

The two men once again locked eyes, but both refused to lose their cool just yet. ''I'm here.'' Gibbs assured their unknown nemesis. ''What do you want, exactly?''

''Many things.'' It replied after a few silent moments. That ruled out the possibility of this being a recording. ''But all I wanted from you personally, was the chance to test out my new creation on some…unwilling subjects. Thankfully your team fitted that bill.''

Now his gut was well and truly screaming at him. Threatening him was one thing, but this guy was asking for a quick death if he even laid one finger on any of his team. Vance's quick glance in his direction suggested he was thinking along the same line.

''I know what you are thinking, Gibbs. I can assure you that your agents have only been exposed to a very small dose. Their lives are not in danger. I cannot say the same about their sanity.''

That really started to have Gibbs worried. If he was a normal person he might even have punched the desk by now.

''Tell me, have any of your precious colleagues had trouble sleeping recently?''

He thought back to how DiNozzo and McGee were acting that morning. They both looked exhausted and decidedly confused. Oh crap.

''Your silence speaks volumes, as they say. You may find that all three of your agents will become more and more…unhelpful as time progresses. They may find that sleep-deprivation is not the only problem they suffer from. I can't have your little NCIS machine operating in full swing. It might get in our way again.''

Gibbs had heard enough of this overconfident rambling. ''You think we won't still stop you?'' He asked in the strongest voice he could muster. ''You're stupid enough to call us, you're stupid enough to get caught.''

They thought the long pause on the other end of the line signaled the end of their little verbal contest. But then one last, chilling sentence met their ears.

''You underestimate me.''

And with that, the line went dead. The tension in the room was alive and flourishing, however. Gibbs aimed one steely look at his director before they both swung round and headed for the door. They started marching towards the bullpen with authoritative purpose.

…

''Anyone remember where Gibbs went?''

Tony's voice broke the comfortable silence in the bullpen. He'd secretly been trying to remember the departure of his boss and which direction he went in, but couldn't seem to. In fact his short term memory seemed to be all over the place. There was at least three occasions where he'd read an entire page on his cold case file, only to discover that he hadn't actually taken any information in. He blamed the lack of sleep as a likely reason for his mental dysfunction, but couldn't shake off the feeling of being somewhat lost. It was as if any sense of professional purpose had abandoned him.

''Gibbs left?'' McGee asked with a confused expression. ''Wait, was Gibbs even here?''

Tony considered the probie's question for a few seconds. He realized he didn't actually have a confident answer to provide his colleague with. Come to think of it, was he imagining Gibbs' presence earlier? That would explain how little he remembered about any previous interaction with his boss that morning. Although, besides the odd head slap or barked order, Gibbs barely ever interacted with any of them at all.

''Have you two bumped your heads?'' Ziva's familiar voice interrupted the ever wondering DiNozzo mind. ''He literally went upstairs to see the director five minutes ago.''

He had? Tony must've missed that.

''DiNozzo, David, McGee with me!''

Speak of the devil, the bossman swept back into view with a new sense of urgency. Vance was with him, so he must have given them a new case. It must have been an important one as well, because they both seemed a little pissed off. Tony was pretty sure he wasn't to blame for this apparent anger. At least, he couldn't remember being behind it anyway. What the hell was wrong with his brain?

Ziva was the first to stand up in response to their boss' order. ''Have we got a case now, Gibbs?'' She asked in a hopeful tone. Clearly she was bored of her previous task.

''Yeah.'' He confirmed in his usual no-nonsense manner. ''But we're not working it until all three of you pee in a cup.''

This news brought a half frightened, half confused look to the Israeli's pretty face. Clearly further elaboration was needed, but their boss never offered any. Luckily for all the confused agents, Vance was on hand to provide the missing information.

''That cell you busted last week was a lot bigger than we thought.'' The director told them in a typically calm tone. ''The guy running it claims to be using you three as his human guinea pigs for a new chemical weapon.'' That caused six eyes to widen at him in fear. ''Apparently there's been no fatal dosage, but we need to run some tests. Right now.''

All these new developments made Tony's head hurt. So he'd been poisoned or something? They all had? Could that explain why he felt so confused and hazy all of a sudden? He supposed he would get answers soon, but was kind of worried about what they'd be. Eventually he fell into step with the group of his peers being led by Gibbs towards the elevator. His best option right now was to just stay on his boss' six. It always worked in the past. He just hoped this particular situation didn't continue to be as baffling as it was right then. If a terrorist group was planning an attack, whether it be a personal one on team Gibbs or something much bigger, then his mornings were about to become a lot less boring. No more cold case files were going to be looked over any time soon.

Yep. Things were about to get interesting, alright.

Don't know what your first impressions are, but don't be shy to post them in the reviews. I literally just improvise these stories as I go along so if it's just a confusing mess then sorry. If not, I hope you enjoyed the opening chapter. The 2nd will be up very soon. I promise it'll explain why Ziva wasn't feeling any effects of the 'formula' as well.