Descending close behind my guide, Beppe Villa, my head rises when I hear shouts coming from a few hundreds metres to the right. A second guide is traversing fast towards us, his skis rattling on the glass-like snow. I stop as the men talk and reach for their mobile phones. I learn only later that they are calling Alberto, their friend and another guide, who, while leading his group, has fallen down a crevasse.
I'm high on one of the world's most famous descents, the Vallée Blanche. A continuous off-piste run of nearly 20km, it offers even intermediate skiers with reasonable fitness and a sense of adventure the chance to marvel at one of the Alps' most stunning regions in the shadow of Mont Blanc. Of course there are risks, posed chiefly by shifting cracks in the glacier, but they remain happily slim and the valley has become a must-do for any skier who itches to leave the piste far behind.
Typically, valley baggers arrive from Chamonix, rising to almost 3,850m at the top of the cable car at Aiguille du Midi, surely the world's most dramatic lift station. A hairy walk follows before the descent starts. It can be the most dangerous part of the day if it's icy or busy, which it invariably is. I've chosen instead to join the descent from Italy and Courmayeur. The lesser-known resort lies just through the Mont Blanc tunnel from Chamonix but offers a quieter and, well, more Italian way to explore the mountains for which its cross-border neighbour is so celebrated.
I've come with friends. It takes us more than half an hour to drink in our surroundings from the top of the vast terrace at Punta Helbronner. We'd started early, ascending via a series of cable cars of increasing ricketiness to almost 3,500m. Mont Blanc dominates 360 degrees of crisp, jagged skyline, appearing so close you might consider a quick descent after lunch. Beppe, a taciturn former shopkeeper from Milan, lifts a worn finger like a sausage to point out Divine Providence, an apparently vertical triangular rock face that forms one of the toughest ascents. He was the second Italian to conquer the route.
The terrace and the cable cars are being replaced in an ambitious project designed to lure more skiers to the Italian side of the valley. Until then, the steps down to the start of the descent are less alarming than those from the Midi, but they're to be taken carefully. So too are the first turns, which can be hard and icy. Mine are rink-like after weeks of dry, warm conditions. Beppe is leading us rightwards in search of less-tracked snow when the call comes about Alberto. We later learn he has recovered after being winched out by helicopter, and after a few minutes of waiting, we head left to join the main drag through the centre of the valley.
On days like this, you come here not for the quality of the skiing but to feel like an ant in awe of its surroundings. High up, we pick our way through house-sized blocks of brilliant blue ice. Later, as the valley flattens, we peel away from the throng to find a secluded rock for the sort of lunch only high mountains can deliver. Jackets off, good bread, hands slightly chilled, total silence but for the occasional rockfall, the trickle of meltwater and the squawking of crows echoing for miles off the valley walls.
Eventually, after some sweaty hiking (the ease of your exit depends on snow conditions – ask your guide first), we ski into Chamonix and a beer at sunset before a 30-minute bus ride back to Italy through the tunnel.
Courmayeur is one of the bigger destinations in Italy's Aosta Valley, which also includes Champoluc, Cervinia and Gressoney, but retains its Alpine charm with cobbles and heavy slate roofs. I am staying at the Villa Novecento, a comfortable four-star affair about five minutes walk from the centre of town. There, the charming main pedestrianised street has shops, bars and bakeries and, near the guides bureau, a quaint Alpine museum that preserves the town's heritage.
The day after our Vallée Blanche adventure we head for local slopes. This involves a short bus or hotel shuttle ride across the river to Dolonne, from where a gondola speeds up to the base station at Plan Chécrouit. Much of the skiing here is spread on two sides of a ridge, each offering challenging pistes for intermediates (this isn't the best resort of beginners) and good off-piste opportunities, conditions permitting.
Mont Blanc rules here and you'll gasp as you reach for your camera at high points Cresta d'Arp and Cresta Youla. At La Chaumière, a pizza restaurant with a vast terrace where desserts are translated as "the sins of gluttony", I have a delicious dish of wild boar sausages with polenta.
Later, we round off two days of challenging skiing, and some fairly involved eating, with a taxi ride four miles out of town to the thermal baths at Pré-Saint-Didier. A restored complex of Victorian-era pools and steam rooms, it now also features modern massage facilities. Outside, I soak my mountain-weary limbs and take to the glass-clad sauna while looking up at a moonlit Mont Blanc through the vapours and steam. For a moment, even the crowds of canoodling Italian couples around me seem to disappear.