This is the story of the great Gaelic hero Fionn MacCool and why he sucks his thumb. This traditional Gaelic tale is retold as an action story to read aloud. It introduces children to storytelling and to Gaelic oral tradition, language, culture, and belief systems. The action story presents gestures corresponding to nine keywords in the story. As the story is read aloud, children perform the matching gesture whenever they hear each keyword. The book contains two versions of the action story, the first entirely in English, and the second in English with Scottish Gaelic keywords. Once children become familiar with the all-English version, the second version with Gaelic action words can be introduced. The actions are the same in both versions, and act as a bridge to introduce the Gaelic vocabulary and increase awareness of the language.