Descending through mist on Ben Macdui, Norman Collie began to hear footsteps behind him. Every few steps he took were followed by a heavier crunch, as though another walker were covering the same ground with a much longer stride. He could see nobody. He listened again, tried to dismiss what he was hearing, and continued down the mountain. The sounds continued too. Eventually, the experienced mountaineer became so frightened that he fled, stumbling among the boulders for miles towards Rothiemurchus Forest.