A/N: This is my almost annual Halloween story. It's all from Gibbs' POV and it's probably not what you're expecting. :) It's not long, just a few chapters.

Disclaimer: I do not own NCIS. I haven't even watched it for years. I'm making no money off this story.

Impostor
by Enthusiastic Fish

Tell me that you were never real
You need another soul to steal
You're my impostor
You tell me you were never really real
~Impostor by Red

Chapter 1

Gibbs pulled up at the diner for his usual morning coffee fix and was surprised to see it closed with obvious smoke damage. He got out when he saw the owner.

"Oh, Agent Gibbs, I'm so sorry to tell you that we'll be closed for a while," she said, sounding genuinely regretful.

"What happened?"

"We don't know yet. Everything was fine when we closed up yesterday, but it looks like something shorted out. All of our coffee machines are damaged and there's a lot of smoke and water damage inside. We can fix it all but it's going to take time."

Gibbs nodded.

"I can make my own coffee. Did it a lot of years before now," he said.

"But then, you might stop coming here altogether," she said.

Gibbs grinned. "You'd go broke."

She laughed. "I might."

"I'll check back. Any idea how long it will take?"

"Probably at least two weeks, maybe a month."

"I'll check," Gibbs said.

"Good. I promise that we'll be back."

"Okay. Good luck."

"Thanks, Agent Gibbs."

Gibbs nodded and went back to his car. It was disappointing but he'd made his own coffee plenty of times... like every weekend when he wasn't at work. Getting his coffee here was simply convenient and better than what he could get at work. He'd be happy to go back to that routine once they were open again but until then, he could easily manage with the coffee had at home. He'd just have to get a bigger coffee cup.

He headed off to work. There was always coffee there. He just didn't care for it much, but it would do in a pinch. He smiled to himself when he remembered Kate spilling his coffee and he'd refused to drink the stuff they had there. It had mostly been on a whim, but it had been entertaining at the time.

Gibbs strode into the building, got a cup of the coffee from the break room, grimaced at the taste, and then headed back to his desk. Tony was already there working, and the elevator dinged right as Gibbs was sitting down. Tim came walking in, but he looked a little bothered by something.

"What's up, Tim?" Tony asked.

"Nothing," Tim said. Too quickly.

Tony's brow furrowed, but Tim sat down at his desk and prepared to get to work. Then, the elevator dinged again, revealing Ellie. No one was late today.

"Tim, who was that guy outside?" Ellie asked.

Gibbs looked at Tim who grimaced for a moment.

"It was nothing."

"It didn't look like nothing. I was ready to make sure he knew there was a witness."

"A witness to what, McGee?" Gibbs asked, getting to his feet.

"It's nothing, Boss," Tim said, but avoided making eye contact, a sure sign that he was lying.

"What did you see, Bishop?" Gibbs asked, looking at Ellie who seemed nervous about suddenly being in the middle of something.

"Well..."

"What did you see?"

"There was this guy and he was pushing Tim."

"Pushing him?" Tony asked.

"Yeah. He shoved him and he was saying something but I couldn't hear it. I wasn't close enough. He looked like he was going to get violent but then he walked away."

Gibbs turned back to Tim.

"Well?"

"He said he... was Landon Gray's brother."

"Who?" Tony asked.

"Landon... the guy who got... obsessed with my book," Tim said, looking unhappy about the subject.

Even Tony backed off, knowing how much that incident had bothered Tim.

"Oh, sorry, McGee."

Tim shrugged with false nonchalance.

"He said Landon wasn't getting out and it was my fault."

"How?"

"I testified at his hearing last week," Tim said. "The prosecutor wanted me to say how I had been affected by his actions and whether or not I'd feel safe with him out of prison."

"You never said anything about that," Tony said.

"No, I didn't," Tim said. "He was mad is all. I told him that I only told the truth and that I wasn't trying to cause any problems. He said it was my fault...and..."

"And what?" Gibbs asked.

"He said he'd get even."

"That's not nothing, Tim," Tony said.

"He was upset. That's all. People do that all the time."

"No, they don't. Bishop, find out where he is."

"You're making more of this than you need to, Boss!" Tim said, getting to his feet. "It's not..."

"It is, McGee," Gibbs said. "You were threatened. That's not going to stand. His name."

Tim sighed. "His name is Jonas Gray."

"Okay," Ellie said, tentatively.

Then, an awkward silence fell as everyone got to work. Gibbs knew what part of the reason for Tim's reaction was. He felt it was his fault to some degree. He didn't want to get anyone else in trouble when he thought he started it. Was it worth forcing the conversation right now? Probably not. Later, if it was warranted.

By the end of the day, Ellie had got information on Jonas Gray.

"So... um..."

"Get on with it, Bishop," Tony said.

"Jonas Gray. Older brother of Landon Gray. Kind of the polar opposite of Landon," Ellie said, tentatively. "Landon had been working in a coffee shop."

"Yeah, I know," Tim said.

"McGee," Gibbs said with a warning in his voice.

Tim said nothing.

"That was just the latest in a string of not-so-great jobs. He flunked out of college. Just couldn't get his life going. Well, Jonas Gray is kind of a computer whiz. Not so much programming as building. His job involves designing interfaces for computers, works for a tech company in Alexandria. Not married. Seems to be focused on his career... and his brother."

"Any criminal record?" Tony asked.

"Nothing," Ellie said. "As far as the law is concerned, he's squeaky clean."

"Or never caught," Gibbs said.

"Look, you guys, I get it," Tim said, finally intervening. "What he did was wrong, but there's no history of violence here. He was upset and blowing off steam. We don't need to make his life harder by ruining his record."

"What if he wasn't, Tim?" Tony asked. "Then, you're opening yourself up to this guy getting revenge or something."

"Only if the worst-case scenario is right and based on his history, that's not likely. I'll watch for him for the next few days and if anything happens, I'll tell you, but unless something like that happens, let's just let it go. Please?"

Tony and Ellie looked at Gibbs. It was his decision at the end of the day.

"For now, McGee," he said, "but if you see something..."

"I promise, I won't hide it."

"Okay. Go home."

Everyone left and Gibbs headed home himself.

x.x.x.x.x.x.x

Over the next few days, Tim promised faithfully that he'd seen no sign of Jonas Gray. It appeared that he was right. There were no further confrontations. As far as that was concerned, things were fine.

But Gibbs had a strange feeling. He didn't mention it to anyone, but there was a feeling of something just beyond his view, someone or something just outside of his peripheral vision. Something with malevolent intent. He didn't know what was causing it, but it made him feel more on edge.

Then, one morning as he was walking out of his bathroom, he thought he saw something in the mirror. ...besides himself.

He looked back quickly.

Nothing was there. He stared at it silently for a long time. No sign of movement. He figured he must have imagined it. So he turned away, and again, he thought he saw something. He turned back and stared at the mirror. What had been there? He was sure he'd seen something. He stared at the mirror more intently.

Then, suddenly, he realized that he had to get moving. The last thing he could be was late for work. He grabbed his coffee and hurried out of the house and headed to work.

Tim was already at his desk when Gibbs arrived.

"Morning, Boss," Tim said.

"Any sign of Jonas Gray?"

"No, none," Tim said. "I promise that I'd say something if there was."

Gibbs raised an eyebrow. Had Tim been just a little too quick to reassure him?

"You sure about that?"

Tim looked surprised.

"Yeah, Boss. I promise."

Gibbs just grunted and sat down at his desk, taking a drink of coffee as he did so. All through that day, he felt as though Tim was hiding something from him. It didn't help when he overheard a conversation during the afternoon. He was standing in his usual eavesdropping spot.

"Tony... does Gibbs seem like he's acting different to you?" Tim asked, his voice low.

"No, but I haven't really said much to him today. Why?" Tony said.

"He keeps staring at me. This morning, when he came in, he was almost late and Gibbs is never late... and he acted like I was lying to him."

"He's just making sure that you're not trying to deal with Jonas Gray on your own."

"But I haven't even seen him since that day. I wouldn't lie about that."

"Eh, I'm sure it's just your imagination."

"I don't know."

Gibbs came striding in, grabbed his coffee and took a drink, and Tim looked guilty. Gibbs raised an eyebrow at him.

"Something bothering you, McGee?" he asked.

"No, Boss," Tim said and turned to his computer.

Gibbs caught Tony scrutinizing him and gave him a look. Then, Tony went back to work.

x.x.x.x.x.x.x

The next morning, Gibbs was heading out of his bathroom and again, he thought he saw something in the mirror. He turned back to it and was shocked.

Tim was in his mirror.

But Tim wasn't in the bathroom. It was ludicrous to think he would be.

"Boss...I'm so glad you're seeing me, finally. You have no idea."

Gibbs stood there mutely. This had to be his imagination.

"Please, Boss. I really need your help. I've been trying to get to you for days, but..."

"This is ridiculous. It's a trick."

Gibbs turned around and started to leave the bathroom.

"No, Boss. It's not! He's trapped me here and I can't get out! It's not me at work! It's an imposter! Please!"

But no. This couldn't be real. He grabbed his coffee, left the house and headed to work, hoping that the diner would be repaired soon.

...but he couldn't forget Tim's voice and his frantic plea for help.

When he got to work, he sat down at his desk and decided to watch for any out-of-character behavior from Tim. Surely, an imposter, no matter how good, would slip up somewhere.

Tony came in and sat down at his desk with only a glance in Gibbs' direction.

"Where's McGee?" Gibbs asked.

Tony's brow furrowed. "I assume he's on his way, Boss. Why?"

Gibbs raised an eyebrow at him and took a drink of coffee.

"Boss, are you feeling okay?" Tony asked.

The eyebrow went higher.

"I'm serious, Boss. You've been acting a little weird the last couple of days."

"And who told you that? McGee?"

Then, the elevator dinged and Ellie got off.

"Have you seen McGee yet, Bishop?" Gibbs asked.

"No, but he did text me to ask about how traffic was, so maybe he's been caught up in the rush."

Gibbs just grunted and looked at his screen.

About twenty minutes later, Tim came rushing into the bullpen looking very frazzled.

"I'm so sorry I'm late. My phone died during the night and I could have sworn I plugged it in. My alarm didn't go off. Nothing was going right. Won't happen again, Boss," he said all in one breath.

Gibbs stared at him for about thirty seconds, sipping at his coffee all the while, and Tim started to look worried. Nothing seemed wrong... but would Tim really forget to plug in his phone? That didn't seem quite right, but it could have happened. Once.

"Did I miss anything?" Tim asked, looking very uncomfortable under the weight of Gibbs' gaze.

Again, was that wrong? Not really, but was he too uncomfortable?

"Work, McGee," he said, finally.

"Right, Boss."

Tim took a breath and seemed almost relieved. But what was he relieved about?

All through the day, Gibbs was staring at Tim, watching him as he did the most simple or complex of tasks. Tim seemed far too aware of the scrutiny. He avoided Gibbs' gaze as much as possible. At the end of the day, Tim seemed to be trying to escape him. Gibbs was convinced. Something was going on, and he ignored the look he was getting from Tony and headed home, empty coffee cup in hand.

To the mirror in his bathroom.

There was nothing there.

"Tim?"

Then, with a strange flickering, there he was again.

Tim was in his mirror.

"Boss! You're back. Do you believe me?"

"How did this happen?"

"I don't know, but I think..." The image flickered. "I think it was Jonas Gray. He some kind of tech genius. He could do it... if it could be done. I just woke up trapped and I realized I could see you, but I couldn't figure out how to get it so that you could see me. I just kept trying."

"How do you get out?"

"I don't know that yet, either, but... but I think you're going to have to kill the imposter to get me out."

"Why would that work?" Gibbs asked.

"If it's some kind of an android or something, the mechanism might be what's keeping me stuck here. But it's not me, Boss. So it doesn't matter if the imposter is dead or not, right? I mean, he'd be the one who did this to me."

Something didn't seem quite right, but Gibbs knew that he wasn't an expert on anything technical. He was just not good at it. So if Tim said it, it must be right. There was still that feeling of malevolence, though. If it wasn't coming from Tim... He turned around.

"What is it, Boss? Someone coming?"

"Don't know. Something..."

He started to leave the bathroom.

"Please, Boss. Don't leave me in here. I'm so afraid that I'm just going to vanish. I don't want to be replaced by someone else."

Gibbs looked back.

"You won't be. Promise."

"Then, you'll kill him? You'll get me out of this?"

Gibbs nodded and then went and brewed himself another pot of coffee. If he was going to figure out how to do this, he'd need the extra caffeine.

But he couldn't rid himself of this strange feeling, like there was something always happening just out of his view. He kept getting these strange flickers of... of things. Sometimes, they were human-shaped, sometimes not.

All through the long night, he kept Tim company and tried to plan out what he would do in order to get Tim free. Tim would talk nervously off and on, like he didn't know how to stop. A lot of it didn't make a whole lot of sense, but Gibbs had tuned Tim out before. He was fine with that now. He had more worries than just believing that Tim was trapped in his mirror.

How could he explain to everyone that he had to kill the imposter that looked just like Tim but wasn't in the worst way? How could he do that? If it was that android thing Tim had suggested, it would be easy, but what if it was actually a person, someone working for Jonas Gray, maybe Jonas Gray himself?

Well, best to rid the world of him anyway. He'd obviously proven himself a menace.

Tomorrow. He'd kill the impostor and set Tim free.