Night Of Knives

Chapter 15

Jacob says, "These are all of Derek's phone calls."

He looks from the computer screen to Veronica. Her expression is hard to read; the half-healed cuts on her once-perfect face make her look like an extra in a zombie movie. Jacob supposes he still resembles an acne-scarred teenager himself. At least his goatee conceals the worst of the damage.

He wishes he'd cleaned up his apartment a little before she came over. It's a nice enough place, two bedrooms all to himself, but it isn't really ready for guests. His bedroom is strewn with scattered clothes and books, and the rest of the place is devoid of furniture except for his computer desk and a couple of chairs. The white walls are bare, the kitchen cabinets are empty, and most of his possessions are still piled in suitcases and toiletry bags. He doesn't even have bookcases yet: dozens of science-fiction novels and technical texts sit in stacks on the carpeted floor of his computer room.

Jacob looks back to his computer, and to the Google Map of Uganda on its screen, a map half-covered by little orange and red balloons that serve as place markers. Red outnumbers orange by a wide margin. Most are clustered in Kampala, but there are a fair number out west, near the Congo border, and a few orange balloons scattered in other places as well.

"Red is Derek," he explains, "orange is the other participant, if they're on Mango."

"Where did this come from?" She sounds more perplexed than impressed.

"Oh." Jacob realizes he has been remiss in providing context. "Derek had a Mango cell phone. Mango is a division of Telecom Uganda. I work for Telecom Uganda and have admin access to their databases. And the reason they hired me is there isn't much I don't know about mobile communications systems. This is what I've got so far. Would have been more, but I spent my first three days back basically fully zoned out."

Veronica nods with understanding.

Jacob switches briefly to a black window full of orderly rows and columns of text. "The records of every call Derek ever made or received, including," he points at columns on the screen, "the other number involved in that call, Derek's location, and if the other participant was also had a Mango phone, their location as well. I converted this data to XML and plugged it into a Google Map. Et voila."

"Location? You can actually track cell phones? I thought that was just in movies."

"No, you can, for real. What happens is, we record which base stations handled the call, and the signal strength they got from your phone. Base stations are the cells, the fixed antennas your phone talks to. We know their exact location. So if three or more were in range, we can triangulate a phone to a single patch of real estate."

"How close can you get?"

"Well, it varies." Jacob decides not to get into too much detail. "Depends on how many base stations and how far apart. Error margin is probably somewhere from forty metres in downtown Kampala to half a kilometre in rural areas. It's not quite like the movies, you can't actually track individuals, because the closer you can get, the more densely populated the real estate, they got lost in the crowd. But you can get a pretty good idea of their general vicinity."

"And you have names too? You know who he called?"

"No. Unfortunately. Mostly. If they're actual Mango subscribers, yes, but almost every phone in Uganda is prepaid, not subscription. But I bet if we look hard enough at this list we'll find some interesting stuff."

"This is why Derek brought you to Africa," she says slowly.

"Exactly. To track the call records of whoever he was interested in."