A/N: Zack is going to start acting a little different. Some might call it OOC, but I prefer to call it character developement based on what I've out him through. But seeing as how I'm the one who wrote it, I guess I have to defend it. But I just can't see him being the naive, wide-eyed kid with all this going on. Hope you enjoy this, please review!

Agent Wilson sat on the opposite end of the couch from Booth, and Zack was back in the chair. Booth noticed with slight amusement that Zack had put on the sweatshirt he had been playing with, and it fit him perfectly. It must have swallowed Casey whole. And somehow, Zack just didn't manage the firefighter look. He still looked like a young boy grieving for his lost girlfriend, but the expression on his face said…well, Booth wasn't sure what his face said, but it was definitely not something he had seen on Zack's face before. On someone else, he would have called it a possibility that the person could become dangerous. On the young squint, it just looked out of place.

Booth quickly introduced himself and Zack, then asked the question that had been trying to leak out of his mouth ever since the new agent had showed him his badge. "So, how do you know Cas…Marti?"

Wilson cleared his throat. "I was the agent originally assigned to her case. I was the one who was supposed to keep her safe."

"Great job," Zack muttered a little too loudly. Booth shot him a look, and Wilson dropped his head. Zack would have regretted causing the obvious pain on the agent's face had this been anyone but Casey. He still refused to think of her by the alien name Wilson was using.

Wilson was a very thin man with short blond hair spiked unevenly on the top of his head. He was almost as tall as Booth, but –what is the word?- wiry, maybe. Silver framed glasses covered sea-green eyes, but didn't give the illusion of weakness glasses sometimes gave men. Instead, it just magnified his eyes, which were already more expressive than most people's whole face. Right now, those eyes were downcast, not so much by Zack's uncharitable words than by the truth behind them. "I've kept an eye on her ever since she came to us. I guess I thought She was safe, and wasn't watching close enough. If I even knew how they found her…" He pinched the bridge of his nose like he had a headache. "I mean, the file is top secret, most agents can't even access it. How did they track her after all these years?"

Booth's eyes widened. "Why couldn't people access the file? I mean, us? That's a little excessive for witness protection, right?"

"Well," said Wilson. "There was some speculation of a leak in the FBI. We think Melissa was tipped off before we got there. Casey wasn't even supposed to be home from school when we got there, so she had to know somehow."

Booth thought he might be sick. This was all his fault. "Then when I ran her name through the computer, someone found her."

"She told you?!" Wilson demanded. "But she knew better!"

Booth felt about two inches tall, and the look Zack was giving him was only a few steps back from frightening. "I made her. I was concerned about what she was hiding, afraid it might be a threat to my team. I told her I would get her fired if she couldn't explain the gap in her story."

Zack jumped to his feet. "I can't believe you! You made her tell you all this, and it could cost her her life!" Booth felt like a heel, and he knew Zack was right, but what he noticed even more was the way he was acting. This wasn't Zack; this sort of anger and unpredictability was Casey, or even Hodgins, maybe even Bones, but not Zack. Quiet, mild-mannered little Zack Addy had come out of his shell over this woman, and Booth realized that the woman who could turn this scared little boy into a man was worth rescuing whether he knew her or not.

Wilson interviened before Zack could show him just how much he had grown. "Calm down, Dr. Addy. Booth didn't realize what he was doing. And that may not even be why it happened. We can't solve this if we're taking out our frustrations on each other."

Zack looked at Booth and reluctantly sat down. "Okay. So what do we do?"

"Well, Melissa was always very popular with the men. We could see if she's visiting any of the local clubs. That's where she tends to recruit her…associates. And then…Hey, what all did you guys touch in here?"

"Not much," said Booth. "At least, this time. Zack is over here a lot. They're…together."

"Well," said Zack "That depends on what you meant by together. We're dating, but if you mean sleeping together…well, technically we have been sleeping together, but not having sex yet." Booth looked at him like he was from another planet. "What do you think I am? She's recovering from a broken shoulder! We wanted to wait until it wouldn't hurt her." Both FBI agents stared at him, and he got it. "Oh, that look meant I should have kept my mouth shut, didn't it?" Booth nodded vigorously, and Zack blushed.

"Let's get this place fingerprinted," said Wilson.

"You think Melissa was here?" asked Booth.

"Not her, but I bet her accomplice was here. We find his fingerprints, we can trace him."

Booth pulled out his cell phone and called for the rest of the squints. While he was on the phone, Wilson looked into Zack's eyes. "I know you're upset, but you have to remember that she is still alive."

"How do you know?" Zack asked softly. Not in a challenging manner, just quietly, plainly, like a young man looking for a reason for hope.

"You must be very smart to have a PhD so young, right?" He nodded. "Well, look at this logically. Someone went to a lot of trouble to convince us that she is dead. If they wanted to kill her, they would have just killed her and left her body, not her sister's." He shook his head. "I thought Miranda had been killed before Marti ran. She said she hadn't seen her sister in weeks. Their mother must have had her locked up somewhere."

Zack shivered. "What was she like? I mean, before?"

Wilson wasn't sure how to answer that. He was sure Zack didn't want to know. "She was…very brave. Scared to death, but very determined to do the right thing." Zack seemed satisfied with the answer, but Wilson had to tell him the last part. "She told me that she didn't come to us to save her life. Said she was doing it because she would be dead soon, and when she was gone there would be nobody left to tell what happened. Then her mother would never be stopped." He straightened his glasses. "Then she said something I'll never forget. It's become my motto: We're the good guys. The minute we forget that, we're no better than the bad guys."

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The three of them were in Booth's car on their way to the lab for an update when Booth's phone rang. "Booth." He listened for a second. "Okay, we're heading that way now." Turning on his lights, he whipped the car around, then turned the light off. "They found a match. Darrell Thomas, released from prison last after ten years for rape and assault. 115 South Vine Street. Let's bring him in."

They turned onto Vine street and got behind the slowest old woman ever born in an ancient brown Pinto. Zack squirmed restlessly in the back seat. "Can't you turn your lights and siren on?"

"Sure, Zack. In fact, why don't I just call this guy up and ask politely if he would start walking and meet us halfway?"

"Should we call for backup?" Wilson asked.

Booth thought. They should. But he wasn't sure it was what he wanted. "Tell me, Wilson, just how by the book are you?"

"I'm in with whatever you're planning. I wish I could shoot every single person involved with her past and the current crisis."

"Zack?"

"Is what you're planning to do going to help us find Casey?"

"Hopefully."

"And punish the ones who hurt her?"

"Yeah."

His deep brown eyes had never looked so frightening. "What book?"