Young Francie O'Sullivan from the Irish family we first met in The Cottage at Bantry Bay has had a successful operation in a Dublin hospital, but longs to return to his beloved family in County Cork. He heads out the hospital door, no permission asked, and finds a train—won't any train do? Francie finds himself making a speedy tour in the opposite direction from home, around the Emerald Isle, a journey full of adventure, laughter, and endearing friendships for Francie and the reader.
"Francie was my favorite character in The Cottage at Bantry Bay. He has been taken from real life and I always felt that, to me, he was symbolic of something ... the Christian principle of the strength of the weak, the valiance of a small one who sticks up for his rights. Francie for me has something of the quality of Jack the Giant Killer, and David in the Old Testament....
"Francie on the Run was thrown into my lap when I was thinking of another book entirely. The picture of him adventuring all over Ireland projected itself between all my imaginings till I had to give way to it. Francie must be heard, his story must be told, he insisted on it. And, I suppose, he determined the story himself as it went on. Once one has a character like him the story more or less writes itself.
"Then, of course, I also had the lovely background for his adventures Ireland as I know it. Francie takes a walk that I have taken step by step myself, and the scenery he meets I have seen with my own eyes. I know the smells of it and the taste of it. The Castle, too, I have known....
"So that, what with Francie's charming personality and the loveliness of his surroundings and the attractive friends he makes, I've enjoyed writing this book!"
— Hilda van Stockum (1939)