Martin Moone is eleven and fed up with being the only boy in a family of girls. With three elder sisters hes desperate for a sidekick to help him fight his corner. When best mate Padraic suggests getting an imaginary friend he decides to give it a go. His first attempt is Loopy Lou who loves practical jokes and is a dab hand at balloon-modelling. But Martin soon gets fed up with Lous clowning around so selects Sean Caution Murphy instead. Sean is much more up Martins street - and full of advice about how Martin should negotiate day-to-day life from dealing with his sisters pranks to beating the bullying Bonner Boys. But getting rid of Lou is not that easy and TWO imaginary friends is a recipe for trouble!
