Anyone who has climbed to the summit of Mont Blanc from St Gervais will know that crossing the Goûter couloir is a game of Russian roulette. You look up the couloir at the same time listening for stone fall. If all is quiet you have about five seconds to cross the death zone at the same time clinging to a suspended rope to avoid slipping. It is not a place for the faint hearted and has been the scene of a number of dramas over the years.