Van overnight in Glen Nevis for early start into Glen Nevis for long days walk. Lovely start to day, up into the hills and the clouds. Interesting navigation issues beweeen the two Aonachs in cloud - easy to choose the wrong 'stone chute' to follow down - could make things interesting. Recognised only with altitude loss, nasty contouring round greasy steep sides to get back to the correct bealach. Decent from Aonachs is quite steep and heard an eerie scream in the mist. Unfortunately discovered that a walker had come off the CMD arête and died in the fall - very sad. Waited while the SAR helicopter attended to continue route with a few other walkers about. Topped out to a very busy Ben Nevis Summit. The way back down to Glen Nevis was solitary and a beautiful alternative way down by the Allt Coire Eoghainn.