While their fighting parents (Clare Dunne & Michael Socha) tear their hair out with worry, runaways Finn (Roman Griffin Davis) and his live-wire younger brother Charlie (Dexter Sol Ansell) embark on an epic adventure from Yorkshire, over land and sea, to the Wild West coast of Ireland. With the free-spirited busker Cait (Maisie Williams) helping the young boys along the way, their destination is Dingle, County Kerry, and their estranged, beloved Grandfather (BAFTA-award winner Bill Nighy), who their parents haven’t spoken to since the fateful events of the previous summer.