The good weather enjoyed for acclimatisation began to deteriorate as the three days ended and the group prepared for the ascent of Mt Blanc. It was decided to delay the ascent by one day, proving a wise decision as the mountain rescue helicopter spent the day ferrying people off the mountain to Chamonix Hospital after storms on top.

On Sunday 12 June the decision was made to attempt the summit early the next day and the group took the Aiguille du Midi cable car up the mountain and made the short traverse down the ridge and across the Col du Midi to the Cosmiques Hut. Here they were treated to a sumptuous feed before attempting to get some sleep before the 0200 start. The group rose a 0100 for breakfast to find a thunderstorm raging outside the hut. The French guides insisted it would clear and at 0300 the storm started to lift. At 0400 the group set out to climb the first section of the route, the shoulder of Mt Blanc du Tacul. This is a vast slope of snow and ice interlaced with crevasses and patches of seracs. After 2¹/₂ hours the group gained the shoulder and stopped to rest. The summit was still under cloud and the horizon was rolling with thick grey cloud and some imposing anvil shaped formations. The conditions were going to worsen and the instructors and group leader decided that to continue would risk the safety of the group and so it was decided to descend to the cable car. This proved a wise choice as the weather quickly closed in and visibility was reduced to a few meters. Even the hardy local guides turned back and retreated with their groups.

The group remained upbeat and accepted that this was a risk of alpine mountaineering. All agreed that the five days mountaineering that had been achieved more than justified the trip. The support the exercise received from the Ulysses Trust allowed the bursars to partake in an expedition that would have been beyond their means. They have all vowed to return and conquer the mountain and admit to having caught the bug for big mountains.