There was a man called Mackenzie who was one of the tenants of Oonich in Lochaber, and after a time it happened that every night his cattle-fold was broken down and the cattle grazed through his cornfield. He was sure that it was neither the neighbours nor the cattle who were responsible, and concluded that it must be the fairies, so he fetched his brother, the one-eyed ferryman — who had the second sight — to watch with him. Late in the night they heard a sound as of stakes being pulled up, and the one-eyed ferryman, moving quietly towards the far side of the fold, saw a dun, polled cow throwing the stakes aside and butting the cattle to their feet. She then drove them through the broken fence into the cornfield. The One-Eyed Ferryman followed her silently, and saw her go up to the Fairy Knoll of Derry Mac Brandy. The knoll opened before her and she went in. The ferryman hastened after her in time to stick his dirk into the turf at the door, so that it would not shut. The light streamed out of the knoll and he saw everything. In the centre of the knoll sat a circle of big old grey men round a fire on which a cauldron was burning. By this time the farmer had come up, but could see nothing until he put his foot on his brother's foot and then the whole scene was clear to him, and he was very much alarmed, and wanted to go away. But the Ferryman called out in a loud voice: * If your dun cow ever troubles Oonich fold again, I will take everything out of the knoll, and throw it out on Rudha na h-Oitire.' With that he pulled out the dirk and the door shut itself They went down home, and the dun polled cow never troubled them again.