A/N – I started this fic at the end of the last season, fully intending to write my own conclusion to the Mexico case before this season started… unfortunately, it didn't happen. So while this starts off with canon events, things change… drastically (esp. starting next chapter). I'm not done with it yet, but if I don't start posting, I'll never finish (but I'm 30+ pages into it and it's mostly outlined). I am, however, headed out on a 2 week road trip with flat!Gibbs (look him up on facebook – I took him 9000 miles around the US last fall) in a week… so.. yeah. Enjoy.

Abby paced back and forth in front of her computer, her phone cradled to her ear. "Like right now? Did the director say what it's about? Can it wait, like, five minutes?" Director Vance's secretary tried to answer each of Abby's questions, but Abby didn't give her time to get a word in. "Be-because, I had a breakthrough in the case and if my Gibbs 'gibbs-o-meter' is working, he should be through that door any minute." She glanced over her shoulder, and sucked in a deep breath as Gibbs strode into the lab. "Oh! Gotta go." She hung up before the words were out of her mouth and spun around to Gibbs. "Do you know something I don't know?"

"Probably not." Gibbs arched a brow; it wasn't like Abby to look so worried.

"Because Director Vance's office called and he wants to see me."

"About what?" He leaned his hip against the table and gave her a concerned look.

"Well, I don't know, but that's the thing. It's like a bad omen. I remember the last time the director wanted to see me. Do you know about the last time the director wanted to see me?" She figured she should test the waters before blurting everything out. Even if it was just Gibbs.

"No." He normally indulged in her rambling, but he had a case that needed to be solved.

Abby's eyes grew wide, "no sense in mentioning that again."

"Abbs." He did know about the last time the Director had called her up, but it wasn't worth bringing up. He moved closer, invading her space. "You said you had a break through? About the case?"

There was something about his close proximity that always seemed to snap her out of whatever rant she was on. "Right! Work. Focus." She inhaled sharply and turned to the computer screen. "So, Ducky ran the tissue…"

Abby rattled off everything she knew but the phone call from Vance's secretary still lingered in the back of her mind. As much as she wanted to go up and see what it was about, there was a sense of dread pooling in the pit of her stomach.

"Good work, give the address to Tony and Ziva." Gibbs handed her a mini-version of her favorite drink. "Nice job."

"What the bio-hazardous material is this?" Abby frowned at the small drink. She could easily down it one sip, she was sure of it, she'd done it before. Twice.

Gibbs shrugged. They had been out of their jumbo-sized cups he usually supplied her with, and he didn't have time to wait for the barista to run to the storage room for more. "It's all they had."

"A mini-pow? This is another bad omen" She held the cup an arm's length from her body and eyed it suspiciously. "Gibbs, this doesn't bode well for my future."

He was in a rush, but Abby seemed generally concerned, so rather than retreating back to the squad room, Gibbs figured he could spare a few extra minutes. Abby and her sanity were worth it. "Abby, I wouldn't worry about it," he said gently, waiting for her to make eye contact.

"Why's that?" She wondered briefly if maybe he did know something that she didn't.

"Because," He moved closer, and gave her his most reassuring look. "I've got your back. Always have," he leaned in and brushed his lips gently across her cheek. "Always will."

Her eyes followed him out of the lab and then Abby smiled to herself. Gibbs always knew the right thing to say to put her at ease. With Gibbs on her side nothing, not even Director Vance, could scare her. Unless he found out about... Abby shrugged. Gibbs has my back.

Abby turned back to her computer and fired off e-mails to Tony and Ziva. Then, giving herself a brief pep-talk, Abby headed for the elevator. She stepped out at the squad room, the team was busy, crowded around the plasma, but Gibbs caught her eye. He smiled and gave a little nod, and Abby felt a flood of relief wash over her. Without Gibbs, this job wasn't worth the stress. Or the long hours.

Abby approached the Director's secretary, Kristina, with caution. "He said I was in trouble, didn't he…?

"Actually… "

"Because I know it wasn't right, but..." Abby rattled on about helping babies and building houses. She knew it wasn't technically allowed, but she figured that if anything, using NCIS's connections to help non-profits were a benefit to all.

Kristina smiled. She liked Abby, but when she was on a roll it was near impossible to get a word in unless you were Agent Gibbs and, on occasion, Director Vance. She waited until Abby sucked in a deep breath, and then cut her off before she could continue. "Remember Alejandro Rivera from the Justice Department in Mexico?"

"Oooh yeah," Abby's lips curved into a seductive smile. The last time she'd seen him, he'd practically undressed her with his eyes. She wasn't interested in starting anything with him, but it was nice to be appreciated, even if it was just for her looks.

"He wants you to fly down to Mexico and speak and some law enforcement symposium."

"Nice!" She hadn't left the DC area in… well, L.A. last year didn't count. "When do I leave?"

"I think today, but the director doesn't want you to travel alone, says Mexico is too dangerous these days, so he's sending an escort."

"Oh God, as long as it's not McGee," Abby rolled her eyes. "I mean he's never been fun to travel with, but lately he's been acting all squirrely since Alejandro tried to undress me with his eyes." She didn't want to start anything with McGee either, but she respected him, and didn't need to rub anything in his face - even if it was just harmless flirting.

As if on cue, McGee rounded the corner. "Uh hi," he smiled at Abby. "The director wanted to see me?"

Abby smiled and shifted her gaze to Kristina. Are you kidding me?

They were on their way out the door, but just before he stepped into the elevator, Gibbs saw Abby heading down the stairs with McGee, both had been up with the director. Sending Tony and Ziva to the car ahead, he offered to meet them out front, and then turned back to Abby. "Everything okay?"

"Oh…yeah." She gave him a pained smile. "Alejandro Rivera has invited me to Mexico to give a presentation on forensics. McGee will be my escort."

Gibbs wasn't fond of the idea of McGee traveling with Abby, but Abby seemed less than thrilled with the idea, so he let it slide. He wasn't jealous of McGee, per say, but McGee had likely seen all of Abby's tattoos whereas Gibbs had only heard about them. "Alejandro Rivera, huh?" He had put up with Alejandro eyeing Abby while he was in town visiting NCIS, but it was troubling that he wanted Abby in Mexico.

Abby smiled. For a split second there was a hint of jealousy in Gibbs' eyes and then it was gone. She couldn't quite figure him out, she thought that deep down there might be something there, but on the other hand, Gibbs was protective of his team, so she couldn't go as far as to what he was jealous of. Her most girly side wanted to believe that he was jealous over her because he wanted her, her logical side said he was jealous of others using her in a professional capacity. He hated to share her with the FBI and they were only a few blocks down the street compared to Mexico.

"Yeah, we won't be gone for more than a few days. I'll call you when we arrive. I need to go pack, we leave this afternoon."

"Be safe, Abbs." Gibbs glanced at McGee who was digging around his desk drawer. "Make sure McGee sticks to bottled water." He leaned in to kiss her cheek again, lingering a little longer than earlier.

"See you soon, Gibbs."

Gibbs' lips twitched into a smile before he headed to the elevator.

The three days in Mexico were possibly the worst three days of Abby's life. The moment she and McGee had stepped off the plane and were greeted by Alejandro, she had known something was off. On paper, the symposium looked great, but something in the back of her mind had been nagging her, telling her to turn around and go home. To Gibbs.

It didn't help that McGee hadn't even made it twelve hours in the country before his stomach troubles started. He had been sure to stick with bottled water, but hadn't given a second thought about eating unpasteurized yogurt.

The class got off to a rocky start, but once Abby had proven that she knew what she was talking about, the students seemed eager to learn from her; asking question after question. They were skeptical at first that she would be able to shed any new light on the cold case that they had been assigned, but as things seemed to fall in place seamlessly, everyone started getting excited.

Then Paloma Reynosa showed up.

Abby's gut had twisted at how crucial evidence had fallen into her lap. Then, when she had a few moments alone, she did a deeper search of their victim. Pedro Hernandez. When a photo of a beautiful woman with glossy red hair and a young girl with piercing blue eyes covered her computer screen, Abby's hand flew to her mouth to try and cover the audible gasp. She slammed the lid of her laptop down, and sat back in her chair, pressing a hand to her chest at the feeling that her heart was about to pound out through her ribcage.

Before, things had felt hinky. The sudden invite to Mexico to work a cold case that had gone unsolved for 20 years. Now, in the course of just a few days, the answers had fallen into place and she knew exactly what happened. The sudden realization that she was being set up to discover undoubtedly Gibbs' darkest secret made her sick to her stomach.

She barely made it to the bathroom before she lost her lunch.

Abby shifted uncomfortably beside McGee on their flight back to DC. He had managed to keep down his breakfast so far, but it was questionable on whether or not he would make it through the flight. As far as McGee was concerned, she was uncomfortable with being so close to someone who could blow any at minute. Abby shifted again in her seat, her mind going over all the details she had uncovered while in Mexico.

In the back of her mind she had always known that Gibbs had tracked down and killed the man that had killed his wife and daughter. It was wrong, and illegal, but on some level she understood. If someone killed Gibbs, she wouldn't sit back and do nothing - she'd put her forensic skills to use.

But more than the case itself, there was something about the way it fell into her lap. Being asked to Mexico and given that case was something she could write off as a coincidence (although Gibbs didn't believe in coincidences, so she wasn't sure she did either), but the leader of a drug cartel riding up with the missing puzzle piece? Someone wanted this case solved and wanted her to solve it.

As soon as they arrived back at NCIS, Abby went out of her way to avoid the team and Gibbs and headed straight for Ducky's lab. She was fairly certain McGee had been too preoccupied with the toilet to notice much, if anything, about the case and she preferred to keep it that way. Alejandro had seemed excited about her solving the case, but she managed to stall, saying she needed everything brought to NCIS for her to continue working on it. If he continued to push for results there would be no question as to who killed Pedro Hernandez.

Gibbs.

She knew if she went to Gibbs he would tell her what to do. He would have no shame in what he did, and there would be no way he would allow her to compromise her ethics and credibility over something he had done twenty years ago.

"Ducky?" Abby hesitated in the doorway of autopsy.

"Abigail, my dear! How was Mexico? By the look on your face I'm wondering if you maybe forgot to drink bottled water."

"Oh no," a small grin tugged at the corner of her mouth. "I know better, but McGee…" she shrugged.

"I told him-"

"He drank bottled water, that wasn't the issue. Unpasteurized yogurt however…"

"I see." Ducky shook his head and then took a step forward, a look of concern on his face. "Oh well, you're hanging in the doorway. Come in, or… has there been another autopsy dream?"

"No, no dream," Abby inched forward.

"I see. Well, I hear you've got a body for me from Mexico. We've just brought him in. Not a usual souvenir, but fascinating none-the-less."

"I need to talk to you."

"I am all yours."

Abby glanced nervously at Jimmy who smiled widely back.

"Oh? Ah, Mister Palmer, could you run those papers I just signed up to the director for me?" Ducky waved a hand back toward the folder sitting open on his desk.

"I can run them up when I…" Jimmy caught the quick glance between Abby and Dr. Mallard. "I'm on my way right now, doctor Mallard. Anything else?"

"Take your time." Ducky dismissed him. He turned back toward his desk to pour them each a cup of tea. "Now, what can I do for you, my dear?"

Abby paced a few times, wondering how to start. She knew that Ducky had known Gibbs the longest, he probably already knew about Pedro, but at the same, this seemed to be bigger than just Gibbs killing the drug dealer that killed his wife. Someone else was involved. "It's about Gibbs."

"Oh?" It wasn't the first time Abby had come to him with concerns about Gibbs. The first was after Kate died and he had taken it upon himself to go after Ari. She had come to him again after his return from Mexico. Then when Hollis has been around. More recently she had come to Ducky to talk about Ms. Hart and the uneasy feeling she got whenever the lawyer was around. "Have a seat."

Abby glanced once around the room to be sure they were alone and then lowered her voice. "He killed someone, Ducky."

"He is a federal agent, and before that a marine. No doubt he's killed people before."

"That's not what I mean," Abby sighed. "At the lecture, they gave me a specific cold case to work. It's a 20 year old cold case, with no new evidence until I went to the scene. I was given this…" She pulled an evidence bag from her pocket containing the old La Pua case. "This is what Gibbs used as a sniper."

"He wasn't the only one to use those; you know the probability of-"

"The dead man's name is Pedro Hernandez," Abby pulled a print out of an old newspaper article from her pocket and handed it to Ducky. She used the back of her hand to wipe at a stray tear as Shannon and Kelly's faces unfolded in front of the doctor.

"Oh, oh dear."

"Yeah."

Ducky read over the article, though he had read it before, long ago. "Well, I can't say I wish Mr. Hernandez had met a better fate."

"That's not the issue, Ducky. Someone is after Gibbs. There are too many coincidences for it to be just a coincidence." Abby explained her entire trip to Mexico; Alejandro bringing her the case, visiting the scene and the visit from Paloma Reynosa, who had so easily handed over the shell. "Ducky, this isn't going to end well."

"There is nothing we can do, you know that. Nothing but be there for him, although I suspect he will be less than accepting. But it's a twenty year old case and… Abigail?"

"What? Oh, sorry. I was just thinking." Abby shrugged. "Just… get me the bullet from Pedro's head as soon as you can, okay? And don't say anything to Gibbs yet."

Ducky's brow furrowed. "What's on your mind?"

"Please Ducky?"

It didn't sit well with Ducky, but he wouldn't say anything, not yet. He assumed Abby needed some time to sort through her thoughts. The least he could do was give her time.

"You wanted to see me, Duck?" Gibbs strode into autopsy and glance at the body on the table. "I hope that's not another victim I haven't heard about."

"Victim, yes, but not our case. I'm helping Abby with one of hers. It's a cold case from her Mexican symposium."

Gibbs didn't even try to hide the irritation on his face. He didn't like sharing Abby with FBI, let alone someone he didn't know in another country. But it was her choice and she had been willing to go. But the way Alejandro looked at her…

"Meet Pedro," Ducky glanced up quickly to gauge any reaction. "Remarkable well preserved for a twenty year old corpse."

"Pedro?" Something clicked.

"I believe so, Mr. Palmer?"

Jimmy flipped through the file and nodded. "Yep, Pedro Hernandez. Apparently he was killed by a sniper when…"

Autopsy disappeared and Gibbs shifted under the heavy heat of the Mexican sun. His fingers itched to pull the trigger, but he needed to wait… one… more… second.

A split second after he pulled the trigger, he saw blood splatter across the windshield and the car swerve off the road. He cried out and clutched his rifle to his chest, visions of Shannon and Kelly clouding his brain.

The sound of Ducky clearing his throat brought him back. "Apparently Abby thinks she might be able to trace the bullet, but… it's pretty old."

"Abby, huh?"

"Yes, but I didn't call you don't here to discuss ancient history. Quite the opposite in fact." Ducky sat the bullet he'd been holding down on the counter and watched casually as Gibbs tracked it with his eyes. He rattled on about their current case – it wasn't far from being wrapped up, but they needed a few last tests done. "Uh, Mr. Palmer, when you finish up, could you run that to Abigail?" Ducky nodded toward the bullet.

"I got it, Duck. I'm headed there next." Gibbs tucked the bullet into his pocket and turned towards the door.

Once Gibbs was out of hearing range, Jimmy cocked his head to the side. "Hm, is it just me, or did Agent Gibbs seem off?"

"Mr. Palmer," Ducky warned.

"Sorry doctor, I'll get back to work."

TBC…