As he was taking the 101 north along the edges of the civic center, Bosch remembered the call from Barbara Starkey. He checked for a message on his phone and heard Starkey tell him to call her as soon as possible. It sounded like maybe she had made a break. Bosch hit the callback button.

“Barbara, it’s Harry.”

“Harry, yes, I was hoping to get to you before I go home.”

“You should’ve gone home about three hours ago.”

“Yeah, well, I told you I would look at this thing.”

“Thank you, Barbara. It means a lot. What did you find?”

“A couple things. First of all, I have a printout here that is a little sharper if you want it.”

Bosch was disappointed. It sounded like there wasn’t much more than what he already had and she just wanted to let him know there was a clearer picture of the view out the window of the room where his daughter was held. Sometimes, he had noticed, when somebody did a favor for you, they really wanted you to know it. But he decided he would just make do with what he had. A jog in off the freeway to pick up the picture would take too much time. He had a plane to catch.

“Anything else?” he asked. “I have to get to the airport.”

“Yes, I have a couple other visual and audio identifiers that might help you,” Starkey said.

Bosch paid full attention now.

“What are they?”

“Well, one I think might be a train or a subway. Another is a snippet of conversation that is not Chinese. And the last one I think is a silent helicopter.”

“What do you mean silent?”

“I mean literally silent. I have a flash reflection in the window of a helicopter going by, but I don’t have any real audio track to go with it.”

Bosch didn’t respond at first. He knew what she was talking about. The Whisper Jet helicopters that the rich and powerful used to move over and around Hong Kong. He had seen them. Commuting by helicopter wasn’t uncommon but he also knew only a few buildings in each district were allowed to operate landing pads on their roofs. One reason his ex-wife chose the building where she lived in Happy Valley was that it had a helicopter pad on the roof. She could get to the casino in Macau in twenty minutes door-to-door instead of the two hours it would take to leave the building, get to the ferry docks, take a boat across the harbor and then cab or walk from the dock to the casino.

“Barbara, I’ll be there in five minutes,” he said.

He exited on Los Angeles Street and headed over to Parker Center. Because of the late hour, Bosch had his pick of spaces in the garage behind the old police headquarters. He parked and then quickly crossed the street and entered through the back door. The elevator up seemed to take forever, and when he walked into the mostly abandoned SID lab, it had actually been seven minutes since he had closed the phone.

“You’re late,” Starkey said.

“Sorry, thanks for waiting.”

“I’m just giving you a hard time. I know you’re on the run, so let’s just look at this thing.”

She pointed to one of her screens where there was a frozen image of the window from the phone video. It was what Bosch had printed out. Starkey put her hands on the dials.

“Okay,” she said. “Keep your eyes up here at the top of the glass reflection. We didn’t see-or hear-this before.”

She turned one dial slowly, reversing the tape. In the murky glass reflection Bosch saw what he had not seen before. Just as the aim of the camera started its swing back toward his daughter, a helicopter moved across the top of the reflection like a ghost. It was a small black craft with some sort of unreadable insignia on its side.

“Now here it is in real time.”

She backed the video up until the camera was focused on Bosch’s daughter and she was kicking at it. Starkey hit a button and it went by in real time. The camera swung toward the window for a split second and then back. Bosch’s eyes registered the window but never the reflection of the city, let alone a passing helicopter.

It was a good find and Bosch was excited.

“The thing is, Harry, to be in that window that chopper has to be flying pretty low.”

“So it either just took off or it was landing.”

“I think it was ascending. It appears to rise slightly as it crosses the reflection. Nothing you can really see with the eye but I measured it. Considering the reflection shows right to left what is occurring left to right, it would have taken off from a location on the opposite side of the street from the building this video was taken in.”

Bosch nodded.

“Now when I look for an audio track…”

She switched to the other screen where there was an audiograph showing different isolated streams of audio she had taken from the video.

“…and take out as much of the competing sound as I can, I get this.”

She played a track with almost a flatline graph and all Bosch could hear was distant traffic noise that was chopped into waves.

“That’s rotor wash,” she said. “You don’t hear the helicopter itself but it’s disrupting the ambient noise. It’s like a stealth chopper or something.”

Bosch nodded. He had moved a step closer. He now knew his daughter was held in a building near one of the few rooftop helicopter pads in Kowloon.

“That help?” Starkey asked.

“You better believe it.”

“Good. I also have this.”

She played another track and it contained a low hissing sound that reminded Bosch of rushing water. It began, grew louder and then dissipated.

“What is it? Water?”

Starkey shook her head.

“This is with maximum amplification,” she said. “I had to work at this. It’s air. Escaping air. I would say you are talking about an entrance to an underground subway station or maybe a vent through which displaced air is channeled up and out when a train comes into the station. Modern subways don’t make a lot of noise. But there is a lot of air displacement when a train comes through the tunnel.”

“Got it.”

“Your location is up high here. Maybe twelve, thirteen stories, judging by the reflection. So this audio is hard to pinpoint. Could be ground level to this building or a block away. Hard to tell.”

“It still helps.”

“And the last thing is this.”

She played the first part of the video when the camera was holding on Bosch’s daughter and just showing her. She brought up the sound and filtered out competing audio tracks. Bosch heard a muffled line of dialogue.

“What is that?” he asked.

“I think it might be outside the room. I haven’t been able to clean it up any better. It’s muffled by structure and it doesn’t sound Chinese to me. But I don’t think that’s what is important.”

“Then, what is”

“Listen again to the end of it.”

She played it again. Bosch stared at his daughter’s scared eyes while concentrating on the audio. It was a male voice that was too muffled to be understood or translated and then it abruptly ended in what sounded like midsentence.

“Somebody cut him off?”

“Or maybe an elevator door closed and that cut him off.”

Bosch nodded. The elevator seemed like a more likely explanation because there had been no stress in the tone of the voice before the cutoff.

Starkey pointed at the screen.

“So when you find the building, you’ll find this room close to the elevator.”

Bosch stared at his daughter’s eyes for one last and long moment.

“Thank you, Barbara.”

He stood behind her and gave her shoulders a squeeze.

“You got it, Harry.”

“I gotta go.”

“You said you were heading to the airport. Are you going to Hong Kong?”

“That’s right.”

“Good luck, Harry. Go get your daughter.”

“That’s the plan.”

Bosch quickly returned to his car and raced back to the freeway. Rush-hour traffic had thinned out and he made good time as he headed through Hollywood to the Cahuenga Pass and home. He started focusing on Hong Kong. L.A. and everything here would soon be behind him. It would be all about Hong Kong now. He was going to find his daughter and bring her home. Or he was going to die trying.