Song entitled 'Laoidh Dhiarmaid' [The Lay of Diarmaid] collected from Coinneach Moireastan [Kenneth Morrison] Trithean 'Clac-Sgiath' [Trien, An t-Eilean Sgitheanach/Isle of Skye] collected on 7 December 1862. The accompanying story tells how Diarmaid always wore a helmet because it covered the 'ball-seric' or 'gradh-seric' or beauty-spot that he had. If any woman saw it she would immediately fall in love with him. One day, while feeding his dogs, his helmet fell off and Grainne, Fionn's wife, saw his beauty spot and fell in love with him. They ran away together and met a 'Ciuthach ban' [a madman], with whom Grainne next fell in love and consequently she left Diarmaid. Diarmaid and the Ciuthach ban then fought, Diarmaid killing the Ciuthach ban and his white dogs. Diarmaid never laid a hand on Grainne and they travelled far and wide until one day while crossing a stream the water came up to her knees and he touched her to help her but she scolded him telling him that for a year and a day she had travelled with three Fenian warriors and none of them had laid a hand on her.

The song begins with Grain[n]e saying, 'Dhiarmuid na freagair na gaothair, Cha 'n eil ann ach faothaid bhreige' and is composed of seventy-two lines and marks some words with question marks. The song tells how after eloping with Fionn's wife, Diarmaid went hunting boar with Fionn on Beinn Gulbain. Fionn knew that the only place that Diarmaid could be wounded was on the sole of his foot, so he asked Diarmaid to measure the boar he had killed with his feet. A barb goes into Diarmaid's foot and he bleeds to death.