“Her job, I daresay,” Lynley said. “The one she held at Empress State Building.”
“Which means that’s where we start?” Barbara asked. “With the team she was on?”
“With that and with FGM.”
“Are you thinking it’s to do with the clinic?”
“She was largely responsible for shutting it down.”
“Mercy Hart, then?”
“We need to find her.”
WESTMINSTER
CENTRAL LONDON
“Good news and bad news is what we end up with.”
Lynley raised his head from gazing at the computer screen upon which played part of the CCTV film that Nkata’s constables had sent over to him for review. Over the top of his spectacles, he saw in the doorway a youthful Chinese woman he didn’t recognize, although she wore police identification round her neck. He said, “Sorry?”
She said, “Marjorie Lee. Forensic tech. We’ve been having a go with that mobile number you sent along.”
“Ah.” He motioned her to enter. He saw she was carrying a manila folder, and she handed him a document from it.
“Here’s the good news,” Marjorie said. “We live in a metropolis. Well, really a megalopolis. So we’ve got thousands of cell towers—literally mobile phone towers—and because of this, the general location of any mobile is fairly easy to suss out as long as it’s on.”
“That’s encouraging. And the bad news?” Lynley looked over what she had passed to him. It was a complicated chart resembling—to his unschooled eye—the navigation charts used on ships before the dawn of satellites, computers, and GPS.
“How much do you know about how this all works?” she asked him.
“I know pinging,” he said. “Although, to be honest, I’ve never quite worked out what pinging actually is.”
“Simple enough. May I . . . ?” She indicated one of the chairs that sat in front of his desk.
“Please.”
She plunked herself into the seat and tucked her hair behind her ears. This bore a streak of burning pink that matched the lozenge-shaped lenses of her wire-rimmed spectacles, which she continually pushed up her nose as she spoke. “Mobile phones are always sending out messages if they’re switched on. They communicate with towers that are placed within cells—these are just designated locations—in a community. If you’re in the countryside, there won’t be a massive number of towers because they’re not needed. If you’re in a city, it’s just the opposite. They’re everywhere. We don’t see them because we’re not looking for them. And mostly, they’re on the top of buildings. Anyway, once you know the mobile number, you can work out where it last pinged. You can also work out the route it took to get to the location of that last ping. But the location of the phone itself is only going to be general at best.”
“What area was the final ping in?”
She indicated the folder she still held, saying, “We’ve got its signal from the Vodafone tower in Hackney Downs, as well as from the Vodafone towers in Regal House, and the Cornerstone O2 tower. Triangulating all the relevant data, we can put you within three quarters of a kilometer of Hackney Downs, from its south-east corner.” She handed him the folder, which he opened to find more charts. She said, “The difficult bit now is that your lot will have to speak to every mobile owner within the circumference of that circle we’ve drawn. At its centre is the south-east corner of Hackney Downs. Where does the owner of that mobile live?”
“Lived. She’s been murdered. She lived in Streatham High Road.”
“Lived. Sorry. Well, it’s possible, if you know her address, to trace the route the mobile phone took to reach the area of Hackney Downs. Is that any help?”
Lynley inserted the materials back into their folder. He said, “I don’t think we’ll need to do that. I’ll let you know.”
“Guv?”
It was Nkata at the doorway to Lynley’s office. As Marjorie Lee left, Nkata came in, nodding to the woman as they passed each other. He said to Lynley, “Th’other DCs on the team finished up with the folders you and Barb brought from the clinic. Only one of them is someone can be located in London, and she says she never went to that place and why would she as she lives in South Lambeth? She says she’s got no clue how her name ended up on a folder there.”
“What did the folder say about why she went there? To the clinic, I mean.”