Eilidh is an orphan who lives with her uncle, aunt and their child. The Family are very unpleasant, greedy bullies. They treat Eilidh very badly, using her a slave to do all the work around the house. Eilidh’s only friend is her Little Black Cat. The two are inseparable, so when her cat goes missing, Eilidh is devastated. A Peddler, passing by the house, tells her that her cat has probably gone to Cat Mountain. Eilidh is determined to go and find her friend, despite the Peddler warning her that the journey is very dangerous. The Family are so surprised by the strength of her decision that they allow her to go.
Eilidh travels to Cat Mountain, a place of dark shadows and threatening sounds of strange, monstrous cats. She finds the village of the cats and her Little Black Cat is indeed there, now able to speak with Eilidh in a human voice. They warn Eilidh that she cannot stay on Cat Mountain, but help her to realise that she has the goodness and courage to survive on her own. They give her a gift to keep her safe on her journey down the mountain.
When Eilidh arrives home, she has grown in courage and is able to stand up to her bullying Family. The gift from the Little Black Cat is revealed to grant Eilidh wealth enough that she is able to live the life she deserves. The greedy Family are jealous of Eilidh’s newfound riches and rush to Cat Mountain to try to get the same for themselves. However, without Eilidh’s goodness and strength of character and the protection of The Little Black Cat, they come to a very sticky end.
The end of the opera sees Eilidh living in comfort, using the gift of the Little Black Cat to take care of those less fortunate than she has become. Even more important than her physical wealth, is the self-belief, courage and goodness she has found through the challenges she has faced and through her friendship with The Little Black Cat.