 Twm and Dai Jones, miners from South Wales, win a coal-cutting competition and take a trip to London to see the England-Wales Rugby match, missing connections with their reception committee. In the big city, innocent Dai soon finds himself accompanied by Jo, an attractive con-woman; while Twm meets a Welsh harpist who leads him through many pubs, and Mr. Whimple of the Weekly Echo is led a merry chase...