This story is about three children who stay with their grandparents for a holiday in County Leitrim in Ireland. This is a misty enchanting place known for its fairy hills, gurgling streams, lakes and hidden caves.They find a baby but it's so tiny, it couldn't possibly be an ordinary child and soon they realise that she's a fairy. They tell no one about her and secretly try to take care of her themselves. Where did she come from and who does she belong to? It doesn't take long for them to find out and that's when the trouble begins.