A/N: Again, I'm no forensics expert, so any errors of fact are mine alone. I know lots of you are following this story (even if the Traffic monitor says otherwise), and I am humbled and grateful.

Rating: T for strong language and mature themes

Spoilers: None.

Disclaimer: I'm still not rich...draw your own conclusions...

Sunday, May 31, 2010 9:06 p.m.

As Gibbs stepped into the elevator to head down to the sub-basement autopsy bay, he mentally reviewed the facts to date, trying to decide whether this murder could be related to the encrypted message that by now had caused a full-blown political disaster for Benjamin Netanyahu. (Interestingly, the Israelis were digging in their heels and defending their actions, in spite of emerging video footage that suggested a heavy-handed and unprovoked attack. They had made no official mention of receiving a tip about the protesters, which suggested to Gibbs that they now realized the message had contained misinformation. Publicly, however, they were still insisting that their commandos were attacked by the pro-Hamas activists, with knives, clubs, and pistols taken from their own soldiers).

If Louisa was the mole, perhaps Halden had figured this out, and threatened to expose her, leading her to eliminate him. It was a half-decent theory, and would also explain her lie about not having access to communications equipment. The daughter of Rear Admiral Hank Penachetti, head of NETWARCOM, would seem to be almost beyond suspicion, simply by virtue of her family name and connections. Except in Gibbs' world (and Tony's, he smiled to himself. The kid had learned well.) They'd both seen too many good people turned bad over the years to give anyone the benefit of the doubt. All the evidence was pointing this way, and Gibbs would follow the evidence to its logical conclusion, whether the result was palatable or not.

The shrill ring of his cell phone interrupted his thoughts, echoing around the steel frame of the elevator. "Gibbs," he answered.

"This is Vance. I need you in MTAC. We have an update."

"I'm just on my way to autopsy. I'll be there in 10."

"Now, Gibbs. This can't wait." Gibbs sighed as he snapped his phone shut. As the elevator doors opened at the sub-basement, just outside autopsy, he caught a glimpse of Ducky, blue-green surgical cap askew on his head, beckoning him to come in. He shook his head with a grimace, held up ten fingers, pointed upwards, and slammed the button to head back upstairs. This had better be good, he muttered under his breath.

9:17 p.m.

Arriving in MTAC a few minutes later, Gibbs glanced at the plasma, which displayed nothing but the striped test pattern. He frowned at Vance, who understood his confusion, and responded, "I think you'll want to sit down for this."

Gibbs joined the Director in the front row of the theatre-style seats. Vance's look of extreme concern made him think maybe this would be worth the detour after all. "So, what's the scoop, Leon?"

"Cyber Crimes completed their trace of the encrypted communique. They were able to source it to one of the workstations in the SIGINT division at NSA."

Gibbs raised an eyebrow. "Let me guess...Petty Officer 1st Class, Louisa Penachetti."

There was a long pause. "How the hell did you know that? I just got this information myself not 10 minutes ago."

"It fits with the facts we've uncovered so far in the Halden murder investigation - Halden figured out what she was up to, so she took him out. I've got David and DiNozzo bringing her in for questioning about the murder. Her fingerprints and hair were found all over the crime scene, and she owns a Glock, could be our murder weapon. This new evidence gives us enough to lay a charge in the national security matter at least. And if Abby matches the ballistics to her gun, and doesn't find any other prints on it, we'll have her on the murder too - you agree?"

Vance concurred, but he wasn't happy. "Admiral Penachetti will be checking in at 22:00 hours. What am I supposed to tell him? Greetings, Admiral. I have an update for you - your daughter is a National Security threat. Oh, and by the way, she also happens to be a cold-blooded killer."

"Well, Leon, that's why you'll never have to worry about me gunning for your job." Gibbs smirked, beating a hasty retreat. With Ziva and Tony tied up at Fort Meade, he and McGee would have to execute the search of the Petty Officer's apartment. The trip to autopsy would have to wait.

Louisa furrowed her brow, staring intently at a sheet of printed gobbledygook. That was Halden's word for undeciphered code (so why was she using it, she wondered?) The computer network was still down, so they were reduced to working from hard copies of older ciphers - SIGINT's version of cold cases.

She was glad he wasn't here tonight. She hadn't even bothered to ask anyone where he was, because, frankly, she didn't care, as long as it was somewhere else. It had been a mercifully peaceful evening so far. But that was about to change.

9:40 p.m.

DiNozzo had been unsuccessful this time in securing the keys to the Dodge Charger, and they made record time to Fort Meade with Ziva at the wheel. He'd felt sick to his stomach before they'd even set out, and by the time they reached their destination, he was ready to throw up. Along the way, Gibbs had called to tell them about the results of the sniffer trace, and instructed them to take Louisa into custody on charges of unauthorized use of military equipment, and making a false official statement. Gibbs and McGee were heading to Louisa's apartment to execute the rest of the search. Tony's heart sank; he might as well kiss his friendship with Pete goodbye right now.

Warrant in hand, they marched through NSA security and up to the SIGINT division. He decided to let Ziva do the honours - he wasn't sure he'd be able to get the words out. Tony had never before felt the slightest qualm about arresting a suspect, especially one accused of such serious crimes. This was just plain weird. He hoped against hope that he was in he middle of some awful nightmare, and that he'd wake up any moment now to find he'd fallen asleep at his desk on Sunday night. But the nightmare refused to end.

"Those spooks are back again!" exclaimed Louisa's co-worker in the adjoining cubicle. Louisa spun around in her chair, just in time to see Ziva pulling out her handcuffs as the two LEOs approached. Her eyes widened in alarm, and Ziva motioned to her to stand. She pulled Louisa's arms behind her back firmly, and cuffed her.

"Louisa Penachetti, you are under arrest for transmitting false information to a foreign government, and using naval computer equipment for unauthorized purposes. You have the right to remain silent. If you give up that right..."

Louisa went weak in the knees; Tony instinctively grabbed her arm to steady her, whispering in her ear, "I'm sorry." His voice caught as he spoke. She stared uncomprehendingly up into his green eyes, tears welling up in her own brown pools, as fear gripped her. Having a JAG officer for a big brother, she'd learned a thing or two about legal procedures, and understood that it was important to exercise the Miranda rights being read to her - she stayed mute, fighting the urge to protest her innocence as she was led back to the elevator in humiliation before her colleagues. She resolved to phone her father at the first available opportunity.

Ziva left Tony to perform the necessary task of searching through Louisa's workstation, and her locker downstairs. He was a natural born snoop, and he had a piece of paper in his hand giving him official permission. His curiosity about Louisa was growing by the hour; perhaps here he would find insights into her personality, suggestions of how or why she could have betrayed the trust she'd been given. Something, anything, that would help him make sense of this horrible situation.

He snapped on a pair of gloves and set to work, ignoring the gawking stares of Louisa's fellow cryptologists. There was nothing of note in the top drawer of her desk, but a file in the bottom drawer caught his eye. It was labelled simply 'Jake'. The SFA opened it and found several dozen 4" x 4" slips of paper, identical to those he'd seen on her desk at home. They were utterly salacious notes, describing all the things Halden wanted to do to her and all the ways he wanted to do them. Why had she kept these? Was she building a case against him? He forced himself to read them all. The very last one was different. Brief, and to the point. I know what you did. Had Halden figured out that Louisa was the one who'd sent the encrypted message? Perhaps he'd threatened to blackmail her? Sex in exchange for silence? Tony swallowed hard. The further this thing went, the more guilty Louisa seemed. But at this particular moment, he was almost glad Halden was dead.

The locker did not yield anything helpful to the investigation, but it certainly gave Tony more of a feel for who Louisa Penachetti really was. It was impeccably tidy - civvies hung neatly on a hanger, a pair of sensible shoes perfectly aligned on the upper shelf. A family photo of Pete, Julia and the kids, and another of her Mom and Dad, in 3" x 5" magnetized metal frames inside the locker door. A mirror, also magnetized. A small cosmetic bag. The faint scent of vanilla and apricot. Fresh and clean. Simple. Understated. Tasteful.

He closed his eyes and leaned back against the bank of lockers with a sigh, allowing the sweet scent to waft into his nostrils, and trying to fill in the blanks about this mysterious woman. There was something different about her... he would never have noticed her walking down the street or at a party, and yet, slowly and surely, she was being imprinted onto his consciousness.

She was a female version of Pete in many ways, it seemed. Pete had a logical mind; an ordered life. Yin to his Yang. Oh, he could be logical when it was required, he was good at that. But it wasn't his natural way. He was a jock. Impulsive. And yes, emotional. Highly intelligent, but sometimes irrational. In essence, Tony was a chameleon, never revealing his true colours. That was what made him so good undercover. He wasn't prone to introspection; he operated purely on instinct.

And therein lay his dilemma. Those instincts were telling him one thing, while every shred of physical evidence they had pointed the opposite way. He knew he needed to step back from this case; but he was reluctant to do so. He seemed to be the only one who was even the slightest bit inclined to consider Louisa's side of the story at this point. And she needed all the help she could get. Once he recused himself, he would lose access to the evidence...and to those who could help clear her name.

His cell phone rang, rousing him back to reality. It was Ziva, waiting impatiently in the car with their silent suspect in the back seat, hands now cuffed in front of her rather than behind her back. Ziva did not consider her a flight risk, and besides, the lithe and fit former Mossad operative could move faster than a diminutive 145-pound woman in handcuffs. "Tony, where are you? Are you almost done?"

He quickly put on his game face. "Yeah. I found something interesting in a file drawer. Just finishing off the locker - nothing here. I'll be there in five." He slammed the locker door shut in frustration, and headed back upstairs, the folder of disgusting notes secured in an evidence bag and tucked under his arm.

McGee had done a quick bit of hacking, and learned that Louisa kept her Glock in storage at the Fort Meade Rod & Gun Club. Access was controlled by biometric security measures - a fingerprint scan was required in order to withdraw the weapon from the storage locker. They obtained an addendum to the warrant, and stopped by the shooting range to seize the gun on their way to Louisa's apartment.

They combed through everything meticulously. They found, and collected, all the little yellow notes from her desk, but little else of any interest. Notably, there was no computer to be seen, nor was there any evidence that one was missing. McGee decided he'd never seen a home so clean and well-organized. And yet, somehow, it still felt comfortable and lived-in. There were little touches of Louisa's personality all over the place... a hand-made afghan was tossed over the back of the pale green sofa... a cello and a music stand filled a corner by the window, across from the desk... lots of greenery and flowering houseplants... various candid family photos perched on shelves and hung proudly in the hallway leading to the bedrooms. In the master bedroom, a sleigh bed made of solid cherry, adorned with a big fluffy duvet, looked very welcoming at this late hour. In the adjoining walk-in closet, everything was sorted, first by type, then by colour: slacks on a pull-out rack at waist height, blouses and jackets hanging above these, skirts and dresses on the end in a section that extended from ceiling to floor. Next to this, a series of narrow vertical shelves, each bearing a single pair of shoes.

The master bath was similarly well-appointed. There were little scented soaps in a seashell-shaped dish on the counter. Fluffy white towels and a lovely thick facecloth hung neatly on a rack, popping against the mint green and lavender walls. Simple, modern wall sconces on either side of the large framed mirror provided cheerful lighting. Large, Italian porcelain tiles surrounded the tub enclosure, accented minimalistically by a narrow mosaic listello at eye level.

There was absolutely nothing in this apartment that screamed 'murderer'. Nothing that suggested she was anything but a by-the-book, straight-as-an-arrow Navy NCO. Sometimes you could just tell by a person's surroundings what they were like, but not always. This one sure had everyone fooled, McGee thought to himself.

He was experiencing a full-blown allergy attack by the time they left; nose running, eyes itching and stinging, and a wicked headache brewing. He knew there must be a cat in here someplace - he'd spotted the litter box next to the utility closet - but Whiskers was making himself scarce. He made a mental note to take Tony to task for not warning him about the cat; the SFA knew very well how badly Tim reacted to felines, and he was sure the omission of this vital piece of information had been deliberate.

11:26 p.m.

Gibbs arrived in Abby's lab with a Caf-Pow in one hand, and an evidence bag containing the Glock pistol in the other. He wanted the ballistics testing done immediately, so that if warranted, he could lay the additional charge of murder.

He was not disappointed. With two-thirds of the Caf-Pow gone, she pronounced: "This is definitely your murder weapon, Gibbs. The striations match perfectly with the .357 Sig cartridge found at the crime scene."

"Prints?"

"Only one set - Petty Officer Penachetti's. Also, while you were gone, I analyzed the pad of yellow paper Tony picked up at Jake Halden's apartment. I was able to lift the impression in the top layer of the pad." She pulled it up on the plasma. I'm going to tell them everything. "What d'you think it means?"

"Not sure yet, Abs. But I have a feeling I'm going to find out in a few minutes. Give me a printout of that, would you?" She dutifully complied.

She yawned. "Can I go home now, Gibbs? I really, really need my beauty sleep." She cocked her head to one side, put her hands together in a prayer-like pose, and gave him her best 'pretty –please' look.

He smiled. "Go." She gave him a big bear hug, yanked off her white lab coat, and pranced towards the doorway. Realizing he was not following her, she turned.

"C'mon, Gibbs! You need your beauty sleep too. I'm shutting 'er down."

"I got it, Abs. Go home." She shook her head in resignation, and made her exit gracefully.

The former Marine stood silent in the middle of the lab for a long moment, mentally reviewing the body of evidence they'd amassed against Louisa Penachetti. He was starting to feel a titch uncomfortable. It was all just a little too convenient. Too obvious. Too incongruous with everything else they knew about her. This was a highly trained, highly intelligent cryptography analyst. Was it plausible that she could really have been so careless as to leave an electronic trail leading them back to her workstation?

And why would she not wear gloves at Halden's apartment if she'd gone there to kill him? For someone so meticulous in her personal habits, it simply didn't fit.

Unless… unless she wanted to be caught.

He straightened his shoulders, turned on his heels and marched out to the elevator, determined to get the questioning of Louisa Penachetti underway. He would get her to reveal her secrets. He always did.

It did not occur to him to stop at his desk on the way to interrogation. Had he done so, he would have picked up an important piece of information, left by Ducky on his answering machine.