The animal flails, frantic and panicking, pushing out an unceasing series of horrid, breathy squeals as its owners struggle to load it into the back of the pickup truck. There are few sounds more gut-wrenching than that of a suffering pig, and this particular porcine complaint marks the low point of what has to have been the worst day of travel during six months in Africa.
We are on the road from Lubango, the largest city in southern Angola, to the border of Namibia, racing against the clock to reach the frontier post before it closes at 6pm on the last of our allotted five days in Angola. We have no idea what kinds of fines and hassle we'll face if we show up a day late, and we're not keen to learn.
"No stopping!" I shout to the driver, in English and - I think - in Portuguese. I'm half joking at first, due to my faith in his earlier assurances that he'll get us to the border on time. In a bizarre and foreboding twist, I've had my wallet snatched from under my nose here in the cab of this vehicle, perhaps by the driver himself or one of his cohorts, but such is our urgency that we push on without making a police report.
• Catch up on all of Scott MacMillan's adventures at Around Africa
Urgency, however, is in short supply in Africa, a lesson we should have learnt well by now. The driver stops often, either to pick up extra passengers - aren't we supposed to have hired the entire car? - or for his friends in the back to buy liquor. There's nothing we can do but shout.
Tempers already frayed, my regret is as palpable as the torrential rain by the time the pig starts urinating and defecating on our already soaked luggage. "This was a mistake," I tell Roger, my travelling companion. "We should have just gone to the police station this morning in Lubango and asked for an extension on our visa. We're not going to make it to the border in time." I sink into resignation.
Actually, after the driver runs out of petrol a few miles from the border and we almost come to blows over our luggage - he has the audacity to demand even more money than we agreed upon - we hop into a taxi for the last stretch, and we're stamped out of Angola at 5.59pm. I'm too drained to feel the relief properly. It's a shame to leave Angola on such a negative note. It echoes with me for days.
Going into Namibia is entering a different world: a flat, paved land of shopping malls and big box stores - and it's English-speaking, to boot. We catch a bus to Windhoek, the sleepy capital, where I rest by a swimming pool for days on end, waiting for the others to arrive: Luke, our companion through Nigeria and Cameroon, now two weeks behind us; and Rob, the overland biker from Brixton who's riding on a fractured ankle.
In Windhoek, I revel in doing nothing, going nowhere, but I don't think Roger can bear the torpor. He signs up for a skydiving course in coastal Swakopmund, a centre for extreme sports. When the others join us, we rent our own car for a camping tour of the country. It's not that we've had it with drivers. Namibia's best sites are just too hard to reach by public transportation.
Our loop takes us from Fish River Canyon, one of the world's deepest, to the ghost town of Kolmanskop, a former diamond mining centre, both in the south; then north again to the desert lake of Sossuvlei, with its deep ochre sand dunes, and up the Skeleton Coast, shrouded with fog and littered with shipwrecks.
Sadly, this camping trip marks the end of the journey for Roger, whom I'd first met in Timbuktu and who's travelled with me all the way from Ghana. Jumping out of all those airplanes, Roger damaged some vital cartilage in his knee. The tissue finally snaps while he's attempting to put up our tents - I was the camp chef, he the tent-putter-upper - in ludicrously windy conditions on a rocky point in Luderitz. He falls over in searing pain, flying back to the UK for surgery days later.
Roger has been an invaluable travel companion (and a main character in this column), so I'll feel strange doing the final leg of the journey without him. I think back to a remark he made months ago, in West Africa, about preserving our nine lives. I think, also, about screeching to a halt next to the "Tropic of Capricorn" road sign south of Windhoek. The result is a corny photo of Luke, Rob, Roger and I, looking like something that comes on during the credits of a bad road movie. It might end up being one of my favourite shots from the trip. Strangers when we set out, we came together on the road to Cape Town and largely stuck together, through illness and injury, from Ghana southward.
Here's the thing. Of the four, I'm the only one who hasn't suffered a personal calamity. Rob fractured his ankle in two places in northern Cameroon, only to stuff it into his boot and continue riding through Gabon, the Congos and Angola; Luke's journey was interrupted by a death in the family, which took him back in the UK. And now Roger's knee. I can't help but wonder if I'm tempting fate when I board the bus to Cape Town.
Scott MacMillan is blogging about his journey on his website, www.wanderingsavage.com