a phone, then you can only track it to one of two locations, where their circles of coverage meet. But Semiliki is way out there. Only one base station."
"So we can't tell where exactly he or the other phone was."
"Probably not. Unless - let me check." Jacob switches back to the black window full of text, and opens up an SSH connection to Telecom Uganda's master database server. His fingers rattle with machine-gun speed over his keyboard as he composes a moderately complex database query, calling up the exact details of all calls involving Derek made near Semiliki.
He runs the query. Telecom Uganda's servers ponder the question for a few seconds; then rows of numbers begin to scroll rapidly down across the screen. Jacob persuses them. After a moment he grunts with surprise. Both the handsets in question, Derek's and the other one, were used far enough away from Semiliki station that their signals regularly arrived twenty microseconds out of sync from their allotted timeslot. That's something. Radio waves move at the speed of light: three hundred thousand kilometres per second, aka six kilometres per twenty microseconds. There's no way to work out the handsets' direction from the station when they were used, but Jacob knows they were exactly six kilometers away.
He relays this information to Veronica, and adds, "Semiliki's a small town, more like a village, there's nothing else out there. And the base station's right in town. So what was Derek doing that far out?"
"Maybe that's the smugglers' hideout?" Veronica suggests tentatively. "Maybe Derek went out there, and that's how he found out too much?"
Jacob frowns. It sounds a little too neat. "Maybe. I don't know. It's not like a secret terrorist cell would have called up a white boy and invited him out to come look at their operation. Tell you what. Let's take a look at what's out there."
Jacob launches Google Earth. A new window opens up on his computer screen, and within it an image of the world as seen from orbit. He copies and pastes data from the other window, instructing the software to traverse the six-kilometre loop around the coordinates of the Semiliki base station. Veronica murmurs with surprise as the image zooms in towards the earth, as if the window was a camera on a falling satellite.
The virtual eye in the sky swoops downwards from orbit, towards Africa, into Uganda. They see roads, forests, clouds over the bristling Ruwenzori mountains south of Semiliki, the blue expanse of Lake Albert to the north, the gray grid of Fort Portal. The virtual camera levels off a few thousand feet above ground and begins to fly in a tight loop. Jacob smiles at Veronica's surprise.
"This is the six-kilometre radius around Semiliki base station," he explains. "What you're seeing are real recent satellite photos, stitched together automagically into a single landscape. Pretty cool, eh? It's like having your very own Pentagon war room, for free."
Hilly terrain scrolls past, and is interrupted by what looks like a wide red scar in the green earth, a blotchy discontinuity several square kilometers in size. The resolution is too vague to see details, but within the red smear, oblong green and gray shapes are arranged in vaguely geometric patterns that suggest human habitation.
"What's that?" she asks.
Jacob freezes and peers at the display. "Must be some kind of town. Weird. Deeply weird. It looks way bigger than Semiliki, but it's not on any of the maps. Let's do a quick web search on latitude and longitude and see what we get."
He launches a web browser.
"Fast connection," Veronica observes. "Mine's really slow."
"Yeah. There's no fiber link to east Africa yet, everything's through satellite, it's a pain in the ass, high latency. But this computer has a DSL connection to the hub, and I've given my personal data the highest priority on their satellite link. Making this literally the fastest Internet connection in Uganda."
He goes to Dogpile.com and types in the geographical coordinates of that mysterious settlement near Semiliki. Dogpile delegates the request to all of the world's major search engines, and assembles the collective results into a single list. The first entry is entitled UNHCR Semiliki.
"UNHCR?" Jacob asks, perplexed.
"I know that one." Veronica leans forward, interested. "United Nations High Commission for Refugees. It must be a refugee camp. Didn't Susan say the camp she worked at was in Semiliki?"
"Did she? But that's not Susan's number." Jacob doublechecks. "No. She's not on Mango. This is another phone. Someone else at that camp."
"Someone else."