Even though they had promised to forget about the mystery lady and her companion, Booth and Brennan spent a restless night after their encounter on the baseball field. Both kids picked up on their uneasiness. Parker insisted on sleeping on the floor of their bedroom (saying he really just wanted to try out his new sleeping bag). Christine refused to sleep at all. Even the infant could sense that something was wrong with her parents and she wasn't happy. Booth had wanted to hold Bones and reassure her that everything was fine. But with both kids hovering, that task had proven impossible. Booth had already decided that this woman must have malicious intentions. Why else did she and her male companion run when he had approached them?

The next morning they took Parker to school and Booth reminded him that he could use his cell phone if anything unusual happened during the day. Parker nodded his understanding and also promised to go straight home after school. Booth debated on telling Rebecca but decided that it could wait until they had more information. Instead of dropping Brennan and Christine off at the Jeffersonian, Booth went in with them. As Brennan took the baby to get her settled at daycare, Booth went to talk to Cam.

"I need security increased."

"What's going on?" Cam laid aside the file she had been working on and turned to face him.

"Some woman has been stalking us."

"Stalking?" Cam raised her eyebrows in surprise.

"I've seen her outside the FBI building. Bones has seen her at the diner and here, outside in the gardens. She made comments about Christine and last night she showed up at Parker's baseball game."

"Is she someone you know?"

"I've never seen her before, Cam. I tried to talk to her last night but she disappeared."

"I'll alert security. Do you have a description I can give them?"

"Yeah, here," Booth handed her a piece of paper that he and Bones had worked on that morning while Parker was in the shower, detailing everything they had noticed about the woman. "If anyone sees her, detain her. I need to know what she wants with my family."

"Is Brennan taking the baby to daycare?"

"She is but she's going to talk to them and let them know the situation. Bones is pretty freaked out, so she may go get her early."

"I don't blame her."

"Yeah, I think I'll check on them before I go."

"Are you okay Seeley?" It had been a long time since Cam had seen her friend this worked up over a situation.

"No, I'm not okay." Booth turned to look Cam in the eye, not trying to hide his fear and anger. "Someone is following me and my family. And I want to know why."

"Listen Bones, if you see her at all today, you call me. Okay?" They were standing outside of the daycare watching Christine through the large windows in the front of the center. Both of them were hesitant to leave.

"Do you think she'll be back?"

"I'm hoping that our little run in last night scared her away but I guess it depends on why she was watching us."

"Angela's working on a sketch then she'll enter it into her computer. Maybe we'll find something that way."

"The SUV."

"What?" Brennan asked as Booth's sudden change in topic caught her off guard.

"Sunday night I saw a red SUV outside the house, and Monday morning they followed us into the city."

"And you didn't find it pertinent to inform me of this earlier in the week?"

"I had forgot actually. I wrote it off as nothing but now-" he stopped mid-sentence, suddenly realizing they had another piece of this puzzle. "I wrote down the plate number." Booth kissed her quickly on the cheek then he took off toward the door, "I'll go run it now. Be careful Bones."

"I will be." She turned to walk back toward the lab but a chill ran through her at the thought of this mysterious lady watching them all week. Cam didn't like babies in the lab but this was different. There was no way Brennan was going to leave Christine alone in daycare today.

Brennan was examining the remains from their latest case as she balanced a half asleep Christine on her hip when Cam walked onto the platform.

"Seriously? Aren't you afraid that this will cause some really negative formative memories?"

"Perhaps, but I can't bring myself to leave her alone right now. She's a very well behaved baby Cam; she won't be in the way."

Cam bent down to pick up Monkey from the autopsy table, holding him out to show Brennan that the baby was already in the way.

"That table is clean."

"Dr. Brennan, I know that you're upset. I understand that, but you can't have her up here. Either go work in your office or let Angela keep the baby while you continue here."

The ladies turned as they heard the beep of a card being swiped at the lab platform.

"Booth sent over the results of a search on the license plate," Hodgins said as he bounded up the stairs. "Hey, you won't let Michael up here."

"I don't let Christine up here either. Dr. Brennan is just about to go back to her office."

"As soon as you tell me what you found."

"Not much actually, the car is a rental. It was signed out to a George Santora on Sunday morning from a rental counter at Dulles. A search of that name comes up empty."

"Empty?" Cam asked.

"Too empty. The address he provided to the rental company is a fake and the credit card he used appears to be untraceable. Chances are George Santora is an alias."

"That's a lot of trouble to get a rental car." Brennan tightened her grip on the baby who had drifted off to sleep.

"Okay I put the sketch I drew into my computer and came up with this," Angela said as she joined the group. She pushed a few buttons on the hand held controls to the computer and an image of the mystery woman popped onto the screen. "Look familiar?"

The other three occupants of the platform shook their heads at first. Then Brennan walked toward the screen, studying the lady's image closely. "Why didn't I notice this before?"

"Notice what Brennan?"

"This woman, she shares a marked resemblance to Booth. I count at least five genetic similarities."

"She does look a little like Booth now that you mention it," Hodgins agreed.

"Booth's mother died when he was a child, there's no way that's her," Cam said.

"I'm not guessing here, Cam. Genetics do not lie. I'm going to go call Booth." As Brennan left the platform her friends shared a confused look.

"It's not possible Bones. My mother is dead."

"Do you have any photographs of her?"

"No, Dad said they were all lost when we moved after Mom died. I've never seen a picture of her." He handed the photo back to Brennan. "Any chance it could be her sister? Or a cousin?"

Brennan took another look at the picture in her hands and sighed. "I suppose that's possible Booth but the genetic similarities to you and Jared are very striking. Regardless, even if it is another family member that doesn't answer the question of why she's following us. Why not just introduce herself?"

"I don't know Bones, all I know is that my mother is dead. This isn't her."

"When did she pass away?"

"I was seven, Jared was three. She was killed in a car accident. I was young but I still remember Dad telling us."

"You were seven? That's old enough to remember Booth, does this look like your mom?"

He stared at the photo, shaking his head, "Maybe Bones, but I don't know, it's been too long."

"Maybe we need to show Hank."

Hank bounced his great-granddaughter on his leg, laughing as she amused herself by blowing little bubbles of spit. "So what's with the unannounced visit in the middle of the week? You two aren't already expecting another baby are you?"

"It would be very irresponsible of us to have another unplanned pregnancy this close after the birth of our first child."

"Didn't stop you the first time."

Brennan smiled. She appreciated Hank's frankness in a way that Booth didn't. He instead chose to cut straight to the point.

"Someone's been following us Pops. We wanted you to look at a picture for us."

"How should I know who's been following the two of you?"

Brennan held out the print out of Angela's computer reconstruction for Hank to see.

"Hand me my glasses." Brennan traded the old man's glasses for her daughter and Booth noticed the flicker of recognition in Hank's eyes as soon as he got a good look at the picture.

"Is it her?"

"It sure looks like her Shrimp, but there's no way. Your mother has been dead for over thirty years."

"Could it be her sister or another relative?" Booth refused to let himself believe that his mother was alive.

"Your mother had a sister, but they didn't resemble one another very much from what I remember."

"Booth, it's her. It has to be. This is the age she'd be now, there are too many genetic similarities to dismiss and Hank remembers her. It has to be her."

"It all makes sense Bones, except that my mother is dead."