The years they passed like a flowing stream in a highland vale shrouded in green. The Fianna marched with Fionn at their helm, though older and wiser this lord of the realm. He was loyal to his king, Cormac Mac Art and to his daughter would give his heart. Her name was Grainne, noble and fair, but to marry Fionn she would not dare.
A feast was prepared in Tara’s great halls, marriage banners adorned on the walls. Grainne sat pale as the feast began then she spied Diarmuid and to him she ran. “My heart is filled with longing for you” she whispered to Diarmuid, he knew not what to do. “Grainne, so fair, with eyes like the sun, please, do not tempt me; do not anger Fionn.”
She did not listen and she did not care; she enchanted Diarmuid with her fiery stare. He was under a geis to do what she pleased, (though) he did not resist or ask for release. During the night when the Fianna did sleep, through Tara’s great halls, the lovers did creep. They fled through the night, to where they knew not, away from Fionn. They dared not stop.
The cry of hounds they heard in the night. They ran until they were far from sight. Days became weeks and still they fled; if caught by Fionn, they would both be dead. One night as they lay in a forest so dark, they pledged their love, gave each other their heart. They made love that night on a bed of grass, two lovers united, never to part.
For a year and a half, the chase went on. Wherever Fionn looked, the lovers were gone. They were aided by Aengus, many a time. He was father of Diarmuid, a warrior fine. Aengus grew tired of this bitter pursuit; he met Fionn and the king to try end the dispute. Neither were pleased, but they did agree. They could live in peace; they were now free.
Fionn relented and gave them some land. They lived in peace and all was grand. Years passed by and the lovers grew old; they had four sons who grew mighty and bold. Diarmuid longed to go hunting with Fionn, like in the old days, when they were young. One fateful night, he opened the door; there stood Fionn; they were friends once more.
There was feasting that night and stories told. The two merry men remembered the battles of old. They planned to go hunting at first light, though Diarmuid heard cries throughout the night. The Boar was a beast he would not hunt, from the wildest swine to the smallest runt. To kill it would bring his own demise. This curse he had carried all his life.
When morning came, Diarmuid set out. He remembered those cries and was filled with doubt. He came upon Fionn at the top of a hill. There was blood on his hands; he looked ready to kill. “A boar is loose, it has killed my hound.” Fionn pointed to the beast that lay on the ground. There then came a crash and the boar attacked. It struck Diarmuid hard and broke his back.
As he fell down, he stabbed the boar. He killed the beast; it was no more. “Fionn, help me, I’m dying and you have the gift of healing, get water, I’m starting to drift.” Fionn ran to the stream and cupped his hand, but the water fell through and soaked into the sand. He tried again, this time with success, but when he returned Diarmuid was dead.
Grainne fell ill when she heard he was dead. She cursed Fionn and Fianna, oh, how her heart bled. “Diarmuid, sweet Diarmuid, I will always love thee; I will never forget the way you loved me.” She lived on her own for some time on her land, until Fionn did come to ask for her hand. This time she agreed; Fionn had mended his ways. They went to Kildare to see out their days.