Author's Note: I'd like to thank phnxgrl, southerngirl1, and MaineCastle for their reviews. MaineCastle: I like having Karpowski in this story, even if she's only occasionally. I'm curious why she was only in two episodes in the second season. I guess her character stuck with me for some reason. This chapter starts right where the last one left off. Enjoy!

Chapter 15

Beckett walked into I1 with Castle right behind her. Esposito had been standing in the corner of the room with his arms crossed, and when she arrived, he handed her the folder and left the room without a word. Beckett glanced at Gretkov, then sat down and started reading through the file. Gretkov had been in an interrogation room several times before, so there was no point to going at him head on. Beckett wanted to make him uncomfortable, throw him off balance. He was used to being shouted at; this time they were going to use silence. Castle positioned his chair so he could read over Beckett's shoulder. The case file was filled with information on all of Gretkov's arrests, so there was a lot of material to read.

Half an hour went by without a word. Every once in a while, Castle would point to something and Beckett would nod or shake her head, but nothing was ever said. Beckett didn't even glance in the suspect's direction, she just watched him in the sliver of her vision between the top of the folder and her eyelashes. At first Gretkov looked bored, but then the silence started to get to him. He started glancing from one to the other and then at the mirror, trying to figure out what was going on. Eventually he started shifting in his chair, a clear sign that he was uncomfortable.

That was the signal Beckett had been waiting for, though she gave it a few beats before talking. "Tell me about John Conklin."

Gretkov tried to play dumb. "Who?"

"John Conklin."

"Never heard of him."

Beckett took a sheet of paper out of the folder. "You're gonna want to rethink that answer. This is a copy of his phone records. Your number shows up twelve times in the last two weeks alone."

Gretkov held out his hands. "Okay, okay, so maybe I knew him, so what?"

"So we think you beat him up because he owed you money." Castle moved his chair back to its original position.

"I don't know what you're talking about."

Beckett took the phone records back. "Foma, I don't really care if you did beat him up. John's dead, so he's not pressing charges. I want to know about his debt."

Gretkov looked surprised. "Wait, John's dead?"

"Yep."

"Hey, look, I had nothing to do with that!"

"We know the beating isn't what killed him, that's why I'm not interested in it. I want to know about his debt."

Gretkov looked relieved. "Paid in full."

"When?"

"Three nights ago. Two days after I... reminded him of how much he owed me."

"How was it paid?"

"In cash. All $20,000 of it."

Beckett glanced down at Conklin's financial records. "He didn't have that kind of money in the bank. Where'd he get it?"

Gretkov shrugged, looking extra confident, which told Beckett he was lying. "How should I know?"

"Foma, I've been doing this job a long time, which means I know when someone is lying to me. How did John Conklin get the money?"

Gretkov sighed. "He took my advice. I gave him a name and number for someone who could help. They would pay his debt as long as he did something for them."

"What kind of something?"

"Don't know, don't care. As long as I got my money, I'm happy."

Beckett leaned forward; pen poised to write the information down. "Give me the name and number."

Foma Gretkov was handed over to the Organized Crime boys for his loan sharking business. Because Beckett had said she wasn't interested in the Conklin beating, Gretkov's admission that Conklin owed him money would go a long way to helping Organized Crime make a case against him. In the meantime, Beckett had Ryan run the name and number Gretkov had given them.

Unfortunately, Ryan's information was less than promising. "Okay, so the name is probably bogus and the number belongs to a burner. No address, no GPS."

"Is there any way to track it?"

"If it was making an active call, we could try to triangulate the signal, but otherwise it's a no."

"Okay, give the number to Tory and have her keep an eye out. In the meantime, I'd like to try setting up a sting."

Esposito came in with a folder. "Hold that thought for a moment. CSU just came back on those partial prints. We might have an I.D."

"Who?"

"Andrea Sheppard. Her prints are on file from when she was a schoolteacher, but her teaching certificate is expired now."

Ryan ran the name. "She has a real estate license now; works for Berman and Brown Realty."

"Why don't you guys go pick her up, Castle and I will try to see if Conklin ran into her at all; maybe fill in a few more blanks."

"You got it."

Andrea Sheppard wasn't at the real estate office, but her boss said she was out with some clients and gave them access to her schedule so they could get the addresses she should be at. The first two were complete busts, but at the third one they arrived just as she was leaving the building with a couple. Sheppard said goodbye to the couple, asking them to think about it and get back to her as soon as possible, before heading toward the nearest subway entrance.

They intercepted her before she got there. "Andrea Sheppard?"

She looked up in surprise. "Yes?"

"Detectives Esposito and Ryan, NYPD. We need to ask you a few questions down at the station."

"Can this wait till I'm off work? I have another client in a little bit."

"We already took care of that with your boss. Come with us, please."

The ride back to the precinct was quiet. The detectives didn't want to tip their hand and have her call a lawyer. Sheppard didn't seem to know what was going on, and she didn't ask. Ryan suspected she might be scrolling through her memories; trying to figure out why two detectives needed to talk to her so badly.

They were in I1 before she spoke again. "This is about the sewer explosion the other day, isn't it?"

"What makes you say that?" Ryan closed the door and took a seat.

"The whole way here I was trying to figure out what I'd done that would make the cops interested in me and then it hit me. That thing I hid in the sewer; it was a bomb, wasn't it?"

Esposito was sitting backwards on his chair. "You mean you didn't know what it was?"

Sheppard shook her head. "No. I owed a bookie some money. $5,000. He told me about this guy who paid people's debts if they did favors for him. At first I thought that meant sex, but when I called, that's not what I was told to do."

"What did he tell you to do?"

"He gave me an address, told me to go in the middle of the night into the alley next to it, and then call him back. So I did."

Ryan wrote a note. "So what happened then?"

"The voice told me where to go to find that device I hid. It was in a duffel bag. When I found it, he gave me another address and told me to call back when I arrived."

"So you followed the instructions again?"

She nodded. "Yeah. I didn't know what it was, but if it paid my debt, I didn't care."

"What happened when you got to the address?

"I called back and he told me which manhole cover to go to. It was already open. He told me to go down there and told me exactly where to set the device down. I just did what he asked and left."

"You never met this guy in person?"

She shook her head. "Everything was done over the phone."

"And when was this?"

"Five nights ago."

"Who gave you the number?"

She looked terrified. "I can't. He'll kill me if I talk. Him or one of his friends."

"Mrs. Sheppard, you are in serious trouble right now. The device you put in the sewer caused an event that ended up killing a man. If you don't tell us who gave you the number, we can't help you at all."

She took a deep breath, and then nodded. "He's called Gretkov."

Ryan and Esposito were ready with information when Beckett and Castle returned from tracking more of Conklin's movements. Sheppard was currently in holding with the D.A. willing to reduce charges if she could testify against Gretkov and the man who paid her debt in exchange for her services. Of course that deal hinged on their team's ability to apprehend the man behind the curtain. Beckett and Castle walked in to see the boys putting the finishing touches to their information on the board.

Beckett was impressed. "Looks like you guys got a lot of info."

"Andrea Sheppard confessed to putting the device in the sewer. Like Conklin, she owed Gretkov money to the tune of $5,000."

"And she had the same name and number Gretkov gave us?"

"Bingo. Ryan pulled up Sheppard and Conklin's phone records to find the calls. We then got a warrant for the mystery number's records. Only three people ever called or were called by this number. Conklin, Sheppard, and Gretkov."

Beckett's brow furrowed in confusion. "How is that possible?"

Ryan handed Beckett a copy of their records. "Because it's only been active for a month. I've asked Tory to find out as much about the phone itself as she can, but she said not to expect much when the number is all she has to go off of."

"Did Sheppard ever meet the man paying off her debt?"

Esposito shook his head. "She said everything was done over the phone and her records confirm that."

"Well, it looks like you found more than we did. All we have are the stations he was at for the subway. It'll take too long for us to canvass all the businesses and residences in those areas to figure out where he was. Even if we used surveillance footage to narrow things down, it would take too many hours to screen all that footage. I'm thinking we should go for a sting."

Castle got a smirk on his face. "I have the perfect candidate."

"Your mother?"

"It's perfect. She's an actress, so she can stay in character and improvise if necessary, plus she should be allowed to make up for the debacle we had when I asked her to help take the precinct back to the 1970's."

Beckett thought it over for a minute, and then sighed with resignation. "Alright, but she has to stay within our guidelines this time. No unnecessary, elaborate improvising."

"Agreed."

"She does what she's told to do, as long as Ryan or Esposito is with her. We don't want the suspect to get suspicious when his instructions aren't followed."

"Agreed."

"And one last thing."

Castle looked confused. "What?"

"You're the one who convinces Gates to approve Martha."

A/N: What's going to happen next? Leave a comment below, thanks!