Title: When Two Worlds Collide
Rating: PG-13
Category: Case fic
Genre: Gen
Pairing: None currently
Summary: Gibbs is due to retire but first he has to get through one last case.
Disclaimer: The characters herein belong to DPB, CBS, Paramount, et al. No copyright infringement is intended
A/N: Thank you for all your lovely reviews, I love reading them

Eventually Gibbs pulled away, "Lets look at this another way. Rather than trying to find Nahir lets try and find out why Shai was meeting with the marine when he was shot."

Tony slid down to the floor, "This is going to be a long meeting, may as well be comfortable."

The other three joined him on the floor and Ziva began, "I think the marine must have known something about Nahir. I can think of no other reason for Shai to have come into contact with him. Unless…"

She became silent and Tony looked to her, "Unless?!"

"Unless this marine, what was his name staff sergeant…"

McGee spoke, "Mark Miller…"

"Yes! Yes unless this Staff Sergeant Mark Miller had something against Gibbs. Perhaps Nahir had found a way to use him, maybe Shai had discovered he and Nahir had been in contact and he met with the marine to try and persuade him to give up Nahir's location. If Nahir were there too, hidden somewhere in the shadows he would not have thought twice about taking out an asset who had become compromised. He would have shot Shai in the shoulder to hinder his ability to fight back whilst he questioned him to find out how much of his plan had been compromised."

DiNozzo spoke up, "Did anyone do any background on this guy?"

"We did the basics…" McGee said in response, "I spoke to the finance but it was focused around the relationship between Staff Sergeant Miller and Officer Levi. We didn't really look back into his history; we focused on the Mossad angle."

Ziva stood and hit the emergency stop button again, bringing the lift back into action. She paced the small space as it climbed back to their floor; as soon as the doors opened she stormed out of the lift. Stopping at what was once her desk, she glared down at the agent sitting behind it, "Move"

Jen looked up at her, "Excuse me?"

Ziva glared slamming her hand down onto the desk, "I said move! Get out of my way! What part of that do you struggle to understand?"

The three men still standing at the elevator exchanged concerned glances before hurrying over to diffuse the situation; Gibbs spoke first barking at Ziva, "Officer David, with me."

She blinked at him, "what?"

"With me David! Now!"

Ziva quickly backed down and silently followed him out of the room, as Tony attempted to reassure the shocked agent and McGee moved to his desk, beginning to look into the marine's history.

Gibbs led Ziva into one of the interrogation rooms and gently guided her into a chair before crouching in front of her, "What the hell was that all about Ziva? You completely lost control in there… If it weren't for the rest of us I wouldn't have been surprised if you'd ended up snapping her neck…"

Her eyes flashed to meet his, "Of course not! I would never kill anyone unless it was absolutely necessary…" Gibbs simply looked at her, "I would not! Never!"

She looked down and found his eyes filled with concern, "Ziver, what's going on in your head?"

"This is all my fault and I cannot stop it. It is frustrating. I never wanted to put you in danger; I felt taking control of Mossad would keep you safe, now it seems everything I have given up has been for nothing."

Gibbs reached up and pulled her into a hug as she began to sob, "Just let it out Ziver, it's okay…"

She clung to him and cried; he waited for her cries to subside before he held her at arms length and looked her in the eye. "It hasn't been for nothing, what you have done, it's bigger than either one of us alone, and it's bigger than you and me. You have secured the political relationship between Israel and the US. The information you have shared has kept countless people from becoming victims of terrorism."

Guilt crossed her face, "But I didn't do it for all those faceless people. I did it to keep you safe and if I fail now it will all have been pointless."

"Then we won't fail; we caught Ari and we will catch Nahir."

"We didn't catch Ari before he killed Kate, what if Nahir gets one of us first?"

"He won't. We learn from our mistakes Ziva. You, DiNozzo, McGee and I are the most successful team NCIS have ever had. We will all come through this in one piece, okay?" she nodded and he smiled, "So wipe you tears and lets go and see why the marine had it in for me…"

She laughed and wiped her face, "This is serious Jethro."

He rose and nodded looking serious again, "I know… Still it made you laugh."

She followed him out of the room and back to the rest of the team. Tony and McGee rose from their seats as they entered the room. Ziva nodded to the pair of them and crossed to the desk furthest from them. She looked down at the agent, "Agent Whyte I apologise for my behaviour earlier. It was unprofessional and unacceptable; I allowed my frustration to get the better of me. It won't happen again."

Jen nodded, "I understand"

McGee spoke up, "We had to dig a little deeper than we expected boss but we found something. It turned out that Mark Miller had a twin, his parents separated when they were only a year old, and each retained custody of one twin. Mark's mother kept custody of him and when she remarried her new husband adopted the child and Mark took his surname; his twin kept his father's name. They grew up independently but were both aware of the other's existence. The twin was also a marine; they enlisted at the same time and ended up at the same boot camp at Parris Island. We are working on the assumption that this is where they re-established their relationship."

Gibbs cut in, "What have I tod you about assumptions McGee!"

"Yes boss we are waiting for one of the instructors to call us back currently boss but we are talking about a long time ago, there are over 38,000 new recruits every year boss, that's almost 20,000 recruits passing through Parris Island annually. There's no guarantee that he will remember these two at all, let alone in enough detail to know if they had any sort of relationship. Boss the brother's name was Matthew Harding…"

Moretti looked puzzled, "Was?"

DiNozzo turned to the junior agent, "Corporal Matthew Harding was suspected of raping several female officers whilst stationed at Quantico. When he found out he was about to be arrested he took another woman hostage; he attempted to use her as a human shield and escape but he was shot and killed…"

Gibbs spoke up quietly, "By me…"

Ziva spoke up, "I don't understand what Nahir had to gain from this. This marine cannot have known anything about you that Nahir couldn't have easily found out for himself. As a Mossad officer he would have been able to access your file, legally or otherwise… He would have been able to access any personal details he wanted, your address, your current case anything. In fact that's probably how he came to find Staff Sergeant Miller…"

"Easy access…" Everyone turned to look at the voice coming from the corner and Jen elaborated on her point, "As a marine Mark Miller would have been able to gain access to most military facilities without a second glance…"

"That would make sense, but with him dead Nahir will have had to come up with a new plan, that is probably why he came to the house and now he will have to think again. This buys us some time, not a lot but some; especially now he knows that I am here to protect you. This will not prove as easy for him as he had originally thought; his planning will have to be more detailed, more devious to get past me. Have you found him? Any trace of him in Washington at all? A hotel room, rented apartments?"

"Not yet…"

Ziva nodded and crossed to Gibbs's desk, sitting down she began to type, remotely accessing the Mossad database. "I will give you a list of Mossad safe houses in the area; it is possible he is using one of those without our knowledge." She paused and pulled Nahir's file onto her screen, clicking print she rose and retrieved the pages from the printer handing them to Jen, "The first is the list of safe houses; the second is a list of all Nahir's known aliases. He may not be using any of them but it may help track him down."

Jen thanked her and returned to work. The six of them remained within the confines of the office for the rest of the day as teams of other agents searched the addresses Ziva had provided them with. Everyone one of them came up empty and as the sky darkened Gibbs looked to his watched and noted it was already later than the time they normally left. He looked up at the team and announced it was time for them to go home again.