Luisne is a young fairy who lives in the fairy fort of Lios Lurgain in the World of the Sí. As she learns about the World of the Sí and the World of People, she has many adventures with her friends. Luisne is very inquisitive about the World of People or 'The World on Top. There are secret ways to go from the World of the Sí to the World on Top but this secret information isn't shared with the young fairies! But, cleverly, Luisne finds one of the secret ways and she secretly goes to the World on Top with her friend Deirdre. Although they see wonderful things, their pklans don't quite work out ... and the're soon in deep trouble!

There's going to be a big wedding in Lios Lurgain! Luisne's brother, Lugh, is to marry his sweetheart, Eimhear. Luisne and Deirdre and all the young fairies have been invited to the wedding and they're all excited about the big day. But not everyone has received an invitation. One very nasty fairy isn't very happy because he hasn't been invited, and when he arrives at the wedding he isn't there to celebrate!