Trek4Mandela climbers pose atop the Sphinx in the Monk’s Cowl nature reserve with Cathkin Peak and Sterk Horn (right) in the background.
Sterk Horn has loomed large in my dreams - and nightmares - for months now. It’s a 2830m peak that sits to the right of Cathkin Peak, the 3148m flat-topped mountain that defines the entire Champagne Valley in the central Drakensberg.

The last time we were there, two months ago, some of us managed to get to level 3 of the 15 levels that make up the peak. It’s absolutely daunting. In fact, on this Saturday morning, it looks impossible from this angle at the Monk’s Cowl nature reserve car park.

“This is why we do the final ascent to Kilimanjaro in the dark, starting at midnight,” confides Trek4Mandela leader Richard Mabaso. “If you could see what the route was like in the day time, your mind would play tricks on you. Instead, you just keep on going forward, step by step, until you reach Gillman’s Point from Kibo - and from there to Uhuru, the top of Africa!”

We leave for Tanzania on Thursday, July 12. My stomach is roiling at the thought. I’m not the only one. Nobody wants to be disqualified at Kibo Hut, the base camp, from doing the last push to the summit. But no one knows how the altitude will affect them.

Mabaso is determined that everyone will stick together on the climb, practising the discipline and the process that will be followed from Saturday, July 14, when we set out from Marangu Gate hoping to summit at sunrise on Wednesday, July 18, on what would have been Nelson Mandela’s 100th birthday.

So he leads from the front, setting the pace. It’s a blistering pace, way faster than the Pole, pole (Swahili for "slowly, slowly") that will be the mantra on the slopes of Africa's highest peak. We race up to the Sphinx, stopping to de-layer, stripping off gloves, beanies and down jackets. The sun's come out, it's a little warmer than the -3º C when we started in the car park, but many of us are starting to sweat.

Mabaso lets us into a secret: we have to step it up if we are to summit Sterk Horn, which is why he concedes he's been pushing the pace. He flatters and cajoles, giving us three minutes to do the obligatory selfies, have a snack and pack outer layers into backpacks before we're off again.

Up on to the escarpment known as the Little Berg, we head for Sterk Horn in the distance. It is incredibly deceptive. The ascent looks very gradual. We are about to find out that it’s not. Up past Blind Man’s corner, we stop in a thicket of trees nestled in a mini valley.

It's time to get real, Kili real. In Tanzania, we'll summit in groups with the slowest going first. Here we're allowed to split into groups to try to get to the top of Sterk Horn; the only rule is that, wherever we are by 2pm, we turn back and head down.

Everyone opts to be in the first group to leave, but within several hundred metres we are strung out on the slope, organically sorting ourselves into groups - the fittest and strongest racing naturally up the mountain.

The going's hard, but at least the pace is far slower. It's relentless, one foot in front of the other, up one level and on to the other. Eventually you lose count of the levels, until finally we can't go up anymore but have to go around.

It's steep, the path is narrow - mountain goat territory. The wind picks up and it's frigidly cold, then it drops and all that’s left is silence.

The mountains can be capricious, mist can be mysterious, but dense fog can kill, leading climbers to plunge off the edge. Picture: Kevin Ritchie

The view is breathtaking and terrifying all at the same time. Eventually we catch up with the front runners. Guide Phumlane Ndumo has stopped everyone. There’s a berg adder that Tawanda Chatikobo almost put his hand on in front, but the bigger issue is that, although it’s only 1pm, it will still take us 45 minutes to summit. Then we’ve got to head back and, because it’s midwinter, the sun will set by 5.30pm, meaning we won't clear the park in time - and the last leg will be done in the dark, but none of us have torches. It’s an unnecessary risk.

We have to turn back. There's disappointment, but nowhere near what you'd expect. It's soon replaced by an incredible sense of achievement. The altimeter on my watch claims we have reached 2674m above sea level - an ascent of 1319m from the main gate where we started. Kibo to Uhuru Peak will be 1165 during the early hours of July 18.

The big difference will be the altitude. First, though, we have to get back down, which is easier said than done. The slope on either side is sheer. If anyone falls we won't be talking about broken legs but body bags - and still the trail runners run up and down past us. The record to get to the top of Sterk Horn and back from the Monk’s Cowl gate stands at 2 hours and 18 minutes. Put that in context: it took us five hours to go down to the gate alone.

Many did it, inadvertently, on their backsides; a couple of us broke our poles; some like Dikeledi Dlwati and Lynn Forbes had to master the very real fears of being so high up and so precarious. They were the only ones brave enough to speak out. I was more terrified, but I never said anything.

Breakfast at The Nest on Sunday is like the day after a battle - or visiting day at an old-age home. Many of us tiptoe into the dining room as if we were walking over eggshells. Spirits revive over coffee and bacon and eggs, the talk turns to Kili, as always. Now the fear is of altitude sickness and finding ways to counter it.

The Berg, though, has been imprinted in all of us - the incredible unspoilt beauty and the challenge of peaks unconquered. Most of us had never been here before February, now many of us are pledging to come back in summer to try to summit Sterk Horn.

It won’t be the last time we will visit the Drakensberg.

The Trek4Mandela organisers thank Volkswagen SA and Mercedes Benz SA for the kind loan of vehicles to ferry the group from Johannesburg to the Drakensberg and back.