Cath Loduinn is the first part of the Gaelic translation of Macpherson's Ossian and it is divided into 3 parts.

Duan 1,
This synopsis of the story is given in Macpherson's Ossian:

Fingal, when very young, making a voyage to the Orkney Islands, was driven, by stress of the weather, into a bay of Scandinavia, near the residence of Starno, King of Lochlin. Starno invites Fingal to a feast. Fingal doubting the faith of the king, and mindful of a former breach of hospitality, refuses to go. Starno gathers together his tribes; Fingal resolves to defend himself. Night coming on, Duth-maruno proposes to Fingal to observe the motions of the enemy.--The king himself undertakes the watch. Advancing towards the enemy, he accidentally comes to the cave of Turthor, where Starno had confined Corban-carglas, the captive daughter of a neighboring chief.--Her story is imperfect, a part of the original being lost.--Fingal comes to a place of worship, where Starno and his son, Swaran, consulted the spirit of Loda, concerning the isssue of war.--The rencounter of Fingal and Swaran.--Duan first concludes with a description of the airy hall of Cruth-loda, supposed to be the Odin of Scandinavia.