"Kate?"

"Hmmm?"

"Are you awake?"

"M-hmmm…"

Castle wasn't so sure. She hadn't opened her eyes, after all. He watched her, waiting to see if she would. And watched a little longer until he tried again.

"Kate?"

"Castle, I'm sleepy…"

Her eyes were still closed.

"I know. Sorry. What color was that car that you saw following us?"

Which was enough to make her open her eyes. Castle was crouched by the couch, on eye level with her. He smiled at her, enchanted by how adorable she looked when she was half-asleep. Beckett rubbed her eyes.

"What?"

"What color was that car you saw?"

"Dark blue. Why?"

"I think someone has been watching the house…"

Beckett sat up.

"You've been outside?"

"No. I've been watching the cameras on the street." He sat down beside her, picking up the remote. "Watch."

Castle had obviously figured out how to make the playback work on the security system cameras, because he started rewinding one of the videos. When he found the spot he wanted, he hit play. The screen showed a few cars going by – the regular traffic on the quiet street. Then she saw a patrol car go by, a few more cars and then a dark sedan. It looked like every other dark sedan in the world, but Beckett frowned.

"That looks like it," she confirmed. "But it could just be a coincidence…"

"That's not the only time it went by," Castle told her. "In the three hours you've been sleeping I've seen the police patrols every 20 minutes or so and that same sedan has been by 7 times."

"Maybe it belongs to someone in the neighborhood…"

Beckett was suspicious, too, but she wanted to hear what he had to say since she knew he had very good observation skills. He shook his head.

"It drives by going the same direction every time," he said. "If it was someone from the neighborhood coming and going, they would be coming and going in opposite directions. This person is only going the one way, like he's going around the block repeatedly."

Beckett took the remote from him and toggled the camera views until she got one from the street side – a position for just this sort of situation. She rewound until she found the car, and then focused the camera on the license plate.

"What's the pattern, Castle?" she asked, reaching for her phone.

"There doesn't seem to be one," he admitted. "He just comes and goes."

She dialed Esposito's number and informed him what was going on. He didn't stay on the phone long – he didn't need to. She ended the call and tossed off the blanket so she could get up.

"Esposito's going to run the plate, and if it turns out that the car isn't registered to an address in this neighborhood, you and I are going to go play bait again – with several police officers as backup in case this person wants to do more an just follow us." She slipped her shoes on. "And if we catch him following us, we can bring him in for questioning."

Castle was obviously willing. He stood up as well.

"Let's go."

She held her hand up.

"Not yet. We need to wait until Esposito calls."

The phone rang again, and after the briefest of conversations she ended the call.

"Tell me it's registered to someone named Jeremy," Castle said.

"No. Adam. Adam Madison."

"Damn."

"Mr. Madison lives in Rhode Island."

"And so does his car?"

"And so does his car," she confirmed. "Let's go for a drive."

OOOOOOOOO

Ten minutes later they were in the car and driving around the neighborhood trying to pick up their tail. Beckett doubted that it would work – it didn't work the day before, after all – but to her surprise, she found the car in her rearview mirror only a short time later.

"Call Esposito," Beckett told him, handing Castle her phone. "Tell him to have them pick this guy up."

Castle did what he was told, and Beckett didn't even look back. She was confident that the officers would do their job, and instead of slowing down and waiting to see it happen, she drove to the precinct. With any luck, the car was stolen and their suspect would be the one driving. Then maybe they'd get some answers that Castle couldn't provide.

OOOOOOOOO

Esposito and Ryan were waiting at the elevator by the time they arrived.

"Did they get him?" Castle asked. He wasn't patient enough to wait for Beckett to ask.

Ryan nodded.

"Yeah."

"Is it Jeremy?"

"No. Adam Madison."

"Really?" Beckett frowned. "Who is he?"

"Ex cop out of Rhode Island. Retired ten years ago and now he runs a coffee shop."

It was Castle's turn to frown.

"What is he following us for?"

There was a commotion down the hall, and they all turned to watch as their man was taken through a side entrance and escorted to one of the interrogation rooms.

"Now's our chance to find out," Beckett said. "Castle, you stay in the observation room – if this guy knows anything, then we don't want him to see you."

OOOOOOOOO

Adam Madison was forty-five years old. He was a dark-haired man with an intense stare and as a former police officer, Beckett had to admit that he probably wasn't going to be easy to intimidate with the usual methods.

"Mr. Madison, my name is Detective Kate Beckett."

"I know."

"You know because you've been following me around the last couple of days…"

"I know because I know you guys are keeping my sister in protective custody."

"What?"

"I want to see her, Detective," he told her, leaning forward, intently. "I want to know what you have planned for her, and what she's gotten herself into that made her go into Witness Protection."

"What's he talking about?" Castle asked, watching through the two-way window.

"No clue," Esposito replied.

Beckett didn't have a clue, either.

"Who is your sister, Mr. Madison?"

"You're kidding, right?" he asked.

"Who is she?"

"Bridget Hart."