I marvel at the agility and energy of both the dogs. Floyd, being younger, has more stamina, going all over the place, while Sushi, a veteran of mountain trips all over New Zealand, is more economical with her movements, deftly sniffing out the line of least resistance. Joe once met a man who told him, “I don’t know if you have the luckiest dogs in the world – or the unluckiest!” By that, I guess he meant they have an amazingly adventurous life, full of new smells and exciting experiences, but at the same time they have little choice about following Joe to some unlikely places, even mountain tops. Sometimes I bet they just want to curl up and go to sleep.

Being two-legged, Darryn and I start to waver when the gorge tightens. Bush bashing ensues around a waterfall. Joe tries to entice us with descriptions of the beauty of the valley-head. But we rebel. Neither of us wants to return downstream in the dark.

Back at the hut, we eat, then sleep.

On summit day, we wake early. Ahead lies a vertical 1400m of steep climbing. It’s rough, scruffy, bony country, and promises to scuff and scrape us, but hopefully nothing more. Joe came out of his south face encounter with a broken arm; his mate Simon a broken leg. They were lucky to survive. There were no PLBs then, and the pair had to hobble out together in the icy cold these valleys can bring during the depths of winter. They only just staved off hypothermia.

In the cool of dawn, we meander our way up McCallum Stream, which drains Pinnacle’s north-western flanks.

Near a fork, we divert up a steep, eroded gully. Joe leads. He’s a mountain goat, travelling twice as fast as Darryn and me, but seemingly with about half the energy. “ A good climber doesn’t disturb one pebble,” he says, so I try to step very carefully, testing each footfall on the loose, steep ground. Floyd apparently doesn’t know this rule and sends a few small stones down.

After a painful 800m, the gradient eases off, we crest the main spur and can take a rest.

Floyd barks excitedly, and we spot eight chamois – the first of the wildlife we see over the day that will include eight goats, three deer and one hare. I don’t know what a spoodle would do if it caught a chamois, but there was no dampening Floyd’s excitement. “Come here, Floyd!” Joe yells, without much effect. When Floyd finally returns, having lost the chamois, Joe scolds him. “Naughty boy!” and Floyd looks suitably chastened.

After crossing a knob, we face a broad scree slope that fans out from a gully above. On one side, rock ribs dribble rocks into a horrendous looking gulch, but we can avoid this. A few speargrass, buttercups, daisies and the occasional penwiper make improbable homes in this lean country.

Perched equally improbably on the scree slope is a large boulder (don’t think about how that got here, I tell myself), which provides a smidgen of shade. Above, the scree steepens further, then enters a narrow rock gully. It’s vertical enough to be exhilarating, while still within my comfort zone. The dogs need a bit of help in places where the steps are above mutt height. We reach the summit ridge 100m below the summit. An airy scramble – three points of contact – leads to the top. We celebrate with hand and paw shakes. Joe rebuilds his cairn from a previous visit.

It’s breathlessly hot, the sun relentless and the sky almost bleached of colour. We find a small overhang where we can sit in the shade. Joe tells me of one previous climb with the dogs, where they didn’t like his chosen route, and disappeared, finding their way along dog-width ledges, eventually re-joining him on the summit. Occasionally, Sushi has abandoned a climb, and made her way back to the hut or camp, deciding that Joe can continue with his silly game by himself.

It’s not often you can truthfully claim to have 360-degree views, but on the summit of Pinnacle, this is genuinely the case. Cloudy Bay, the Inland Kaikoura Ranges with Tappy, Alarm and Mitre all identifiable, the peaks of Molesworth Station, the Raglan Range, Travers Range, Scotts Knob, Mt Owen and the Arthur Range of Kahurangi National Park, the Red Hills, the Richmond Range all in one great sweeping circle of mountains. I spin around, taking it in. Make mental notes of places I’ve been to; places I’d like to visit.

Joe may have been to this summit six times before, but he’s never traversed the peak, so he scouts ahead to find a suitable route down the south ridge. He returns soon, thumbs up. We follow him, edging our way over some airy down-climbs, with some degree of exposure. I feel pretty comfortable, except when Sushi almost pushes me off-balance. “She likes to stay with the pack,” Joe explains, “and also stay on the safe side of your legs.”

Sharp rocks and scree aren’t kind on dog’s pads, and she limps a bit now, one of her paws cut and showing clear signs of arthritis. In human years, she’s into her seventies. Joe sighs, giving her a reassuring pat. “This might have to be her last climb,” he says.

We reach a loose gut, which steepens up. Darryn leads, and soon we can see the way is clear ahead, down a long, long scree slope into Krushen Stream. I marvel at how well the dogs move downhill. I’m grateful for my hands, to be able to cling to holds when the going is steep. The dogs may have in-built crampons, but they don’t have those most useful opposable thumbs.

From here we get a commanding view of the south face, the one that gave Joe all that trouble years ago. It’s a blunt anvil of a face, daunting, and now dark in the afternoon shadows. Joe points out where the avalanche hit him. He fell about 300m and Simon 150m. Joe broke his humerus; Simon his right femur. It took them 27 hours to reach Boulder Forks Hut, a lot of it in the dark of a long winter night. We’ll cover that same distance in about 3.5 hours.

Joe has not been back since and looks pensive as he searches through the scree, guessing exactly where they might have ended up after the fall. He searches for any remains of gear lost in the chaos of that horrible night. He tells us that even when they finally reached their vehicle, they had to drive themselves to Blenheim Hospital.

Below the scree and snowline, we encounter an unwelcome green alien in the landscape: wilding pines. The invasive trees are colonising the subalpine zone, seeded from plantations to the north-west. Joe says there were none 12 years ago.

A shady spot beside the creek offers relief from the relentless Marl-borough sun. A sort of lazy torpor takes hold, at least for Darryn and I. We decided to sleep and rest for a bit. Before too long, however, Joe gets ants in his pants and heads downstream with the dogs.

After a while, something bites me. It’s an ant, and there’re lots of them. So we head off, too.

We negotiate bouldery cascades, where the roar of the river makes conversation difficult, but lower down easy terraces allow us to talk about life and work.

We reach Boulder Forks Hut late in the afternoon. We’ve been on the hoof for 12 hours. Darryn finds some watercress for a salad, garnished with mint that also grows wild here. It’s been a satisfying day; we’ve traversed Pinnacle, possibly the first party to do so. Darryn and I are grateful for Joe’s leadership and local knowledge, and he’s pleased to have done something new on a mountain he knows well.

The dogs curl up, tired. Sushi ’s arthritis is giving her a bit of trouble. Joe talks to her and pats her. “Good girl!”

Darryn – a vet in a former life – examines her paws. He recommends easing her into retirement. Joe’s been thinking that for a while already. Retirement, he says, will mean cruisey tramping trips, where she can enjoy leaf-cushioned forest paths under her paws. No more snow slopes and rock ribs. I pat her too. She raises her head and licks my hand.

It’s been Sushi’s last climb.