Photographed by Klaus Thymann, Words by Benjamin Leszcz

On the morning of our ice-dive, the conditions are pristine: The sky is cloudless and the sun is bright. The February air is bracing, with the thermostat hovering around −4°F. The water, of course, will be far warmer.

Most people come to Tignes, an alpine village in the heart of France’s Savoie region, to ski. Along with its better known sister resort, Val D’Isère, the area is home to nearly 200 miles of impeccable trails, including a glorious bowl, headed by the Grande Motte glacier and frequently dusted with fluffy powder. But I’ve come here with my friend, the photographer Klaus Thymann, to visit the dark side of the lake, beneath two-and-a-half feet of ice and about three feet of snow. We are not reckless but curious, guided by Jacob Bronowsky’s words: “Man masters nature not by force, but by understanding.”

After the ice-dive-masters, Pierre, Philippe and Manche, brief us in the cosy equipment shed, we don our seven-millimeter-thick neoprene dry suits and amble to the edge of the dive-hole. We sit, our feet dangling into the ominous waters. And then, one by one, we slide out of the sunshine and into the abyss.

Under water, we trace the underside of the ice with our fingers. Near the dive-hole, the ice is scraggy and sloped, eroded by divers’ CO2 bubbles meandering to the surface. Further from the hole and the natural spotlight of the sun, the water darkens and the ice is smooth.

A few feet deeper, Manche swirls his index finger, a bit of dive-master theatrics that creates a slowly rising mini-tornado. Streams of black bubbles intermittently pass by. Schools of hardy trout live here year-round, yet we see no signs of aquatic life; the fish know well that deeper water is warmer water. Roughly 140 feet down, on the lake’s floor, it could as balmy as 40°F.

After about 20 minutes, we return to the dive-hole, our bright blue gloves punching triumphantly into the mountain air. Philippe hoists us out of the water. Klaus and I remove our regulators and share a smile. Our fingers and toes are numb but our mission is complete: We have visited the dark side and returned to tell the tale.