Veronica says, "Where there's smoke there's fire."

Jacob half-smiles. "Except here."

The pale plume rising into the sky half a mile away, seen over the trees that line the road, looks exactly like smoke from a big fire. Even the distant noise sounds like something far away burning furiously. High above, the noon sun is surrounded by something Veronica has never seen before: a perfectly circular rainbow.

She takes a moment to appreciate the beauty, then takes a deep breath and looks back down to earth. No sense delaying any longer. "All right. Let's go."

The road that carried them the ten kilometres from Livingstone to the border ends at a chainlink gate. A series of other fences steer the small queue of pedestrians into a squat building labelled ZAMBIA EMIGRATION. Beyond this checkpoint, a metal bridge about three hundred feet long traverses a steep-walled gorge.

Jacob takes her hand as they wait, holding the small day packs that carry all their remaining worldly possessions. "Almost there."

Veronica forces a smile. This is their fourth border in four days. She knows in theory the line is good - busy officials are likely to hurry them along, bored ones are dangerous - but the anticipation is always worse than the crossing itself. Assuming of course that they don't get caught. A fate more likely to happen here than anywhere else. The tiny posts where they entered and exited Uganda, Kenya and Tanzania were so far from modern networked civilization it will likely take months for those immigration officers to learn that Jacob and Veronica were wanted fugitives, but this is a major transit nexus. When Veronica sees computers beyond the building's glass-fronted wickets, her stomach tenses and she starts to breathe fast.

"Those won't be connected to anything," Jacob says quietly into her ear. His voice is reassuring, but his hand is clammy. "They'll only know if they call in our names. They won't do that unless they get suspicious. And they won't get suspicious. There's nothing suspicious about us. Nobody's even dreaming that we'd come down here. Just stay cool and we'll be fine. If you're shaking, just pretend you're sick or something."

The line edges forward. They begin to near the uniformed immigration officer. Veronica can't believe she's here, doing this, sneaking across a border, hoping to escape an Interpol warrant. It doesn't feel real. Nothing about their epic journey across half of Africa, in the hundred hours since they escaped Uganda, has felt particularly real.

Sunset at the Kenya-Tanzania border, watching clouds of winged termites erupt from a mound the size of a small house, with snow-capped Mount Kilimanjaro looming in the distance beyond. Their roller-coaster early-morning flight to Dar es Salaam, followed by a panicky taxi ride to the railway station, arriving only ten minutes before the departure of the weekly train to Zambia. A young woman moving along the length of the train at one of its many unscheduled stops, selling live locusts, a local delicacy, from a red plastic bowl. Ghostly stick-figure men and women, more like shadows than humans, standing beside the tracks and staring as the Tazara train rolled through the desiccated, drought-blasted hills of southwest Tanzania.

"Passport," the immigration officer says.

Now that she is at the front of the line, in the moment of truth, she feels inexplicably calm and relaxed; her breath has slowed, her muscles have loosened. Maybe she has just run out of adrenalin. Veronica produces her passport and passes it over with steady hands. It seems strange that so much rests on that little blue booklet, that her ability to pass between nations is determined solely by the words and pictures within. The Zambian officer stamps it and hands it back without even looking at her name. Jacob receives the same treatment. Veronica's legs are weak with exhaustion and relief as they walk out of the immigration post. Only one more border post to go, and it should be the easiest of all.

When she steps onto the bridge she gasps aloud at the sudden sight of gargantuan Victoria Falls. The majestic curtain of water to her right, the source of that towering plume that is not smoke, tumbles over a four-hundred-foot cliff into a gorge that curves sharply before passing beneath this bridge. Amid the whitewater below she can see little inflatable blue-and-yellow rafts: tourists rafting the mighty Zambezi. They look like children's toys. More tourists, all white, some looking distinctly pale and nervous, cluster around the bungee-jumping booth midway across the bridge. Veronica half-smiles as she passes. After her last few weeks, bungee jumping seems about as nervewracking as a stroll through a flower garden. She wonders whether she's grown tough or just numb.

There is another lineup to enter Zimbabwe. Veronica is taken aback; she thought this was a pariah state. From the voices and accents most of these would-be adventure tourists are are British, Australian and South African, with a sprinkling of Europeans. Two immigration officers are on duty. To Veronica's relief one is a woman. Yesterday's email from their only hope, their still-nameless contact in Zimbabwe, told them to go to the woman on duty.

They have to fill out forms before presenting their passports. Jacob's hands are now shaking from tension, it takes him three attempts to legibly complete a form, and this makes Veronica nervous too, surely this is exactly the kind of thing they look for, Jacob's face looks pinched and he is sweating heavily, he might as well be wearing a SUSPICIOUS CHARACTER T-shirt - but no one seems to notice. The woman takes Veronica's passport and thirty dollars cash, reads her name, hesitates a moment, then gives her a knowing look through the glass. Veronica doesn't move. The woman smiles slightly, smooths a very modern visa sticker onto one of the passport's last virgin pages, stamps it, hands it back, and waves her on. Jacob rejoins her as they walk into Zimbabwe.

"We made it," she says giddily.

He does not share her euphoria. "We have forty dollars cash left, and we can't use cards. If our man with no name doesn't show, we're finished."

* * *

According to the email, they are meant to meet him outside the nearest Total gas station. A long road winds from the bridge up towards the town of Victoria Falls, past empty fields of dry bushes and grass. They pass little gaggles of white tourists, and a few men selling yoghurt drinks, before they reach a remarkably modern strip mall that boasts a tourist information office, souvenir shops, and the green-and-blue logo of Standard Chartered Bank. A massive and apparently brand-new hotel/casino complex built to First World standards is just opposite. Veronica is amazed: isn't Zimbabwe supposed to be a wretched, dangerous place?

"There," Jacob says, pointing at a red sign. "Total." He pronounces it the French way, stressing the second syllable.

She looks. Like all gas stations, Total has a big board which displays its prices. But this station's board says

PETROL NO

DIESEL NO

PARAFFIN NO

No one is waiting for them outside. The little shop within the station is named La Boutique: its windows are cracked and the door hangs open as if broken. When they enter, the attendant, a young man reading some kind of photocopied book, stares at them as if customers are an unheard-of innovation. The shelves are covered with dusty containers of motor oil and spark plugs, and there are two large Coca-Cola fridges, both empty.

"No Coke?" Jacob asks, disappointed.

"No."

"Do you know where I can get some?"

The young man shakes his head. "No Coke anywhere."

They retreat from this empty shell that was once a gas station. Veronica is more shocked by the absence of Coca-Cola than that of gasoline. She stops between the gas pumps, which are actually rusting from lack of use, digs into her cargo pants and produces her last pack of Marlboro Lights.

"What the hell," she says to Jacob's questioning look, "how often do you get to smoke in a gas station, right?"

He shrugs and takes a cigarette. She looks around. The elaborate casino complex is almost entirely deserted, weeds are growing in its lawns. Two of the souvenir shops are closed. There are no vehicles moving on the street.

A small boy approaches from across the street and asks, "Change money?"

They shake their heads in unison.

The boy looks around furtively, then whispers, loudly, "Are you Jacob and Veronica?"

They stare at him. Eventually Jacob says, "What if we were?"

"You go down to Vic Falls Park. You go to jungle there."

The boy scurries away before they can interrogate him.

"I guess he wants to meet in private," Veronica says.

Jacob nods. "There was a sign for Victoria Falls Park just after the bridge."

They retrace their steps to this sign and follow a narrow concrete path away from the road, towards the falls. Veronica wonders what the boy meant by jungle. It is already apparent that Zimbabwe, like southern Zambia, is a dry country of brown grasses, wiry bushes, termite mounds and thorny trees, nothing like verdant central Africa.

A fat ranger at a guardpost informs them that admittance to the park will cost twenty of their last forty US dollars. Veronica tries to negotiate, but the ranger just stares at them stonily. Eventually she shrugs and pays; what choice do they have?

"I guess we can get money from the ATMs here if we really have to," she says as they advance through the turnstile. "Or a credit card advance."

"I think Zimbabwe's been cut off from the global banking networks. Hyperinflation and failure to make payments, or something."

Veronica winces. If this meeting with their mysterious stranger doesn't pan out they will be out of both money and options."We should have gotten money in Livingstone."

"Then they'd know we were there, and they'd figure out we were coming here. We have to stay completely off the grid. No cards, no phone calls, no international flights."

They advance into forested parkland along a path of cracked and broken concrete slabs. The roar of water grows as they advance, until suddenly the forest opens and they see the falls' entire length edge-on. They are a full half-mile across. A rainbow shimmers amid the whitewater as the mighty Zambezi plunges endlessly over a sheer cliff. In the distance, the gorge bends sharply to the right, towards the bridge. The air is thick with ambient water.

"Look," Jacob says, pointing to the right, to the lip of the gorge opposite the falls. There is a small patch of deep green vegetation where the spray is densest. Surrounded by dry grasses, it looks like an oasis in the desert.

They follow the paths along the dry side of the gorge and into a whole new ecosystem: palm trees, huge ferns, intertwining vines, leaves so dense they block out the sun. It reminds Veronica uncomfortably of the Impenetrable Forest. The concrete slabs in this bizarre patch of jungle are drenched with the perpetual spray, they have to pick their way carefully past mud and puddles.

The man waiting for them is tall and athletic, mid-twenties. His arms are ropy with muscle, his high cheekbones are carved into a statuesque face. His head is so closely cropped it is almost shaved, and his skin is very dark. His movie-star looks are marred by a sickle-shaped scar on his left cheek. He wears jeans, a red T-shirt, and a denim jacket. Something about him, his watchful readiness, reminds Veronica of both Derek and Rukungu.

"Jacob Rockel, Veronica Kelly," he greets them. His accent is African; this is not the nameless man from the phone. "Are you alone?"

After a nervous moment Veronica admits, "Yes."

"My name is Lovemore. Please, wait."

Moments later another man, short and white and tubby, emerges from the path that brought them here. He wears jeans, a T-shirt, muddy boots and a battered leather rucksack, and walks with a slight limp. A shock of brown hair and a dense pepper-and-salt beard adorn a shrewd, professorial face that has seen maybe fifty years.

"Terribly sorry for all this cloak and dagger guff," he says with a self-deprecating grin, shaking their hands casually. "Mostly childish nonsense, if you ask me. But we're living in interesting times here in Zimbabwe, have to dust off a few of the old tricks. Our esteemed government seems to feel the need to keep an eye on harmless old me."

"You're who we talked to on the phone?" Veronica asks warily.

"The very same. Lysander Tennant, at your service, in the flesh. You've met my driver and minister without portfolio." He nods towards Lovemore. Then his face hardens, and his voice, while remaining courteous, turns curt. "Now then. I don't mean to be unwelcoming, but you'll understand, I can't be found harbouring international fugitives without bloody good reason. I really shouldn't be talking to you at all. I'm here only out of that which killed the cat, and a certain morbid loyalty to our dear departed Derek. So you'd best think of this as a job interview. I'll give you five minutes. What happened in Uganda? What do you have for me?"

Jacob looks at Veronica.

She shrugs - what choice do they have? - and says, curtly, "General Gorokwe is going to assassinate Mugabe with surface to air missiles."

Lysander's stony face is wiped away for a moment by sheer amazement. Then it returns and he says, skeptically, "Really. And why would he do a silly thing like that? He wouldn't have a hope in hell of taking charge afterwards."

Jacob says, "He thinks he does. He has American support. This whole thing was an American plan from the start. Gorokwe is just their instrument."

"An American plan?" It takes a few seconds for Lysander to digest those words. He looks at Lovemore, who is listening intently. "That's - no. That's ridiculous. They wouldn't, nobody could be that stupid. That would be madness. Sheer bloody madness."

But this time he doesn't sound dismissive. He sounds worried.

"Maybe so," Veronica says, "but that's what they're doing."

"They who? The White House? You can't possibly expect me to believe -"

"No. A few diplomats and CIA agents who faked that Al-Qaeda scare in the Congo so that the US government would line up behind Gorokwe. Now that he's a friend of America, they'll back him to take over when Mugabe dies. I know it sounds crazy. But that's why Derek died, that's why Prester died, that's why we got kidnapped in the first place, that's why they're after us now. They're going to shoot down Mugabe first chance they get and try to install Gorokwe as president."

Jacob adds, "We have evidence."

Lysander looks from one of them to the other for what feels like a long time. Then he looks at Lovemore, who nods, slowly.

Lysander says, reluctantly, "I suppose you'd better show me."