ACONCAGUA 6,962 METRES.

Morning gear check in Mendoza, last rentals topped up. After lunch we drive 3 hours west along Ruta 7, climbing through the Andes to Puente del Inca, the historic trailhead village. Overnight in a mountain lodge with the wind already changing.

We drive to Horcones entry at 2,950m, hand permits to the park rangers, and step on to the trail. A 4 to 5 hour trek up the Horcones valley brings you to Confluencia camp at 3,390m. First night in tents, first night above 3,000m, first taste of altitude.

A day hike toward the Horcones Glacier and the foot of the South Face. Climb high, sleep low. Return to Confluencia for the night, body ticking on the right altitude curve.

A long 7 to 9 hour trek up the Horcones Superior valley to Plaza de Mulas, base camp for the Normal Route. Mules carry your heavy gear, you carry day pack only. Walk in to the base camp infrastructure: heated dining dome, real chef, hot showers, WiFi, doctor on site.

Full rest day. Hydration, calorie load, sleep, medical check. The body is now figuring out what 4,300m feels like, and rest is the entire job.

Round-trip climb up Mt Bonete to 5,100m, the most important acclim day of the trip. Tests your legs, your lungs and your head at altitude. Descend to base camp to sleep. This single day moves the success-rate needle more than any other.

First load carry up the Direct Route to Camp 1 (Plaza Canada). Cache fuel, food and tents at altitude, then descend to base camp to sleep low. Two altitudes in one day, the climber's oldest trick.

Second rest day at BC. By now the body is well-acclimatized to 4,500 to 5,000m and ready to live higher. Eat. Sleep. Do nothing. The mountain is patient.

Climb to Camp 1 with personal kit plus remaining group gear. Set up camp on a wind-scoured shoulder, sleep at altitude for the first time. Most climbers feel the air change at this point: thinner, harder, real.

4 to 5 hour climb to Nido de Condores, the Condor's Nest, the most sheltered high camp on the mountain. Sleep at 5,550m. The mountain is now openly testing you.

Rest day at Nido. Hydrate, eat, gear check, summit-day briefing. The OJ group leader and the chief guide jointly read the weather forecast and confirm the summit window. Early sleep.

Climb to Camp 3 Colera, the highest camp, with a light pack and your summit-day kit only. Hot meal, gear check, final briefing, early sleep. Wake-up call is between 3 and 4 AM.

Start 4 to 5 AM. An 8 to 12 hour summit push past the Independencia hut at 6,380m, across Cresta del Viento (the Windy Ridge), up the Canaleta, a 400-metre 33-degree chute that is the hardest single section of the climb, along Filo del Guanaco and on to the summit. Descend to Camp 3 to sleep, or push all the way to base camp if the body and the weather agree.

Full descent from the high camps back to Plaza de Mulas BC. Showers, hot meal, sleep at base. The body lands. The brain takes a little longer.

Rest day at base camp. Photos, summit-cross prints, asado celebration, mule loading. The expedition is now in the past tense and you can feel it.

8 to 10 hour trek from BC down to Horcones, then the pickup vehicle drives 3 hours back to Mendoza. Hotel check-in, hot shower, real food, ice-cold beer. The first night in a real bed in two weeks lands harder than you expect.

Recovery day in Mendoza. Optional vineyard tour out at the Uco Valley, where Argentina's best Malbec lives. Group summit dinner in the evening at one of the city's classic parrillas. You earned the steak.

Airport drop and fly home, via Santiago and a bus connection or direct out of Buenos Aires. You leave thinner, prouder, and quietly aware that the Himalayas just got smaller.