the more experienced group, made up of mostly boys, led by Beattie set off and was followed by the less experienced group of four girls and two boys and their two female guides, Davidson and Sunderland. After crossing the plateau both groups were to descend to the Corrour Bothy, at a much lower level in the Lairig Ghru where they would spend the night. Sunset was just before 16:00. The Davidson group would then return, along the Lairig Ghru, while the Beattie group would return by traversing Cairn Toul and Braeriach, on the far side of the valley. In case of emergency each group was to go to the Curran shelter, high on the plateau. That plan had been approved in advance by the head of Lagganlia, John Paisley, who could forbid unsuitable expeditions. Shortly after the groups set off, the weather deteriorated, as had been forecast to the groups' knowledge, but the Beattie party successfully navigated to the Curran shelter, where they dug snow from the door and spent the night. Davidson, worried that her group would not be able to find the shelter in white-out conditions (she knew that it could become completely covered in snow), decided on a forced bivouac out on the plateau. She chose a site at a slight dip at the head of the Feith Buidhe burn, about east of Lochan Buidhe and the Curran shelter. Beattie was not worried about the missing people because he assumed that they had gone to some other shelter. Davidson's group On Saturday afternoon, Davidson had abandoned the original plan when the conditions became poor, and some of the students became distressed. Instead of navigating directly to the Curran shelter, she had headed slightly downhill and aimed for the Feith Buidhe stream in the hope of following it up to Lochan Buidhe to reach the shelter beside the lochan (small loch). The burn was obliterated by snow and so she gave up hope of finding Curran. She prepared to bivouac in what, unknown to her, was a major accumulation area for snow. John Duff, the leader of the Braemar MRT, later considered that to be a serious mistake: "to attempt a winter bivouac, in a storm, on a Cairngorms plateau, is literally a life or death decision, and a last option". He also wrote that the major mistake was even to have considered "an appallingly over-ambitious expedition for