Story about the Lochlannaich [Vikings] and MacNeils which tells how the Lochlannaich built Caisteal Loch Thangastail [Dùn Mhic Leòid, Barraigh/Isle of Barra] and MacNeil's daughter married one of them and lived in the dun there. MacNeil wanted to kill the Lochlannaich because they were getting on in the country so he found out from his daughter what their weakness was and subsequently attacked them at night killing them all. MacNeil's daughter was pregnant and bore a son called Cailein or Caleb and told him how his grandfather had killed his father and his father's people. Cailein plotted revenge but MacNeil, knowing about this killed him. Places which bear Cailein's name are mentioned.