The award-winning Irish K2 documentary The Summit airs tonight (January 6) on RTÉ One at 9.35pm. Paddy Kehoe says it's a must-see.

The Summit is a profoundly captivating film which recalls a terrible tragedy. However, it is also a film which, without trying too hard, salutes simple acts of human bravery and loyalty. It makes the viewer ponder the dilemmas that mountaineers face when trouble strikes. For instance, do you stay to try and help, or descend to save your own life, as lack of oxygen takes its toll and frostbite is a definite possibility if you don't get to camp quickly? That is just one of many moral or tactical dilemmas that surround such adventure.

The catastrophic events recalled and dramatically recreated in The Summit with such ice-cold clarity occurred on August 1, 2008. That summer, more than 70 climbers from 15 expeditions attempted K2, in the Himalayas, the second highest peak on Earth at 8,611km. Eleven climbers, including Limerick man, Ger McDonnell, lost their lives.

Historically, most casualties occur during the descent of K2, as the memorials at the base of the mountain, which is situated at the Pakistan-China border, readily testify. One out of every four people who reach the summit has died on the way down - one wrong step and you are history, as one climber puts it.

Yet when others had descended, Ger McDonnell stayed to help two or three injured Koreans. A precarious, overhang of ice, known as a serac, over 100m high, collapsed on this brave Irishman and the South Koreans, causing their deaths. His brother JJ, and his partner, Annie Starkey, recall the 36-year old, who was clearly a charismatic individual, full of fun and gutsiness. Shortly before his death, he was recorded on film at the summit, saying he was so happy he could almost cry. Ger McDonnell was the first Irishman to reach the summit of the so-called "Savage Mountain".

There is footage of Ger McDonnell singing The Rocky Road to Dublin in a tent, his arm around Sherpa Pemba Gyalje. Pemba, an interesting contributor to the film, is a highly-focused mountaineer who is key to the facts of the tragedy, in so far as they are known. A certain degree of mystery and controversy still dog the tragedy, over five years on.

The Summit celebrates the fearsome majesty of K2 and that shot of its pyramid-like shadow reflected in the sky above China is a beautiful, yet baleful motif throughout this film. A must-see.