Il s'agit de l'histoire du grand héros gaélique Fionn MacCool et de la raison pour laquelle il suce son pouce. Le conte présente aux enfants la tradition orale gaélique et il s'agit du conte parfait pour une lecture à haute voix dans une classe ou en groupe. Les exploits de Fionn MacCool sont populaires à l'échelle du monde gaélique depuis plus d'un millénaire. Les Gaëls de l'Écosse ont apporté l'histoire des exploits de Fionn MacCool en Nouvelle-Écosse il y a deux siècles, et ont transmis les contes oralement d'une génération à l'autre, dans le cadre de leur culture gaélique canadienne.
This is the tale of the great Gaelic hero Fionn MacCool and why he sucks his thumb. It is also the story of the Salmon of Knowledge on the Nova Scotia Gaelic flag. Tales of Fionn MacCool were popular across the Gaelic world, from Ireland to the Isle of Man and the Highlands of Scotland. Scottish Gaels brought tales of Fionn MacCool to Nova Scotia beginning in the 18th century and transmitted them orally from one generation to the next as part of their Gaelic culture. The tale is retold as a participation story, with gestures corresponding to nine "action words" in the story. As the story is read aloud, audience members can perform the matching gesture whenever they hear an action word. The book contains two versions of the action story: the first is in English, and the second is in English but with the action words in Scottish Gaelic. After the audience becomes familiar with the all-English version, the second version with Gaelic action words can be introduced. The actions are the same in both versions, acting as a bridge to introduce Gaelic words and increase awareness of the language. The second edition has been expanded to include engaging new black-and-white illustrations and a version of the tale entirely in Scottish Gaelic.