The Golden Key is a short novel by George MacDonald. The story takes place in a mystical forest called Fairyland. Mossy is a young boy who learns from his great-aunt about a golden key hidden at the end of the rainbow. Mossy does not know what the key would unlock, but he feels a strong desire to obtain it. One evening, while Mossy is looking out of his window, a rainbow suddenly flashes across the sky.  This reminds Mossy of the golden key, so he darts out of the cottage to get closer to the rainbow. To his delight, he reaches the end of the rainbow and finds the golden key.

Meanwhile, not far away, a young girl named Tangle is chased out of her home by fairies. She is led by a strange creature known as an air-fish to the cottage of an old woman named Grandmother. Grandmother then sends out an air-fish to look for someone else. That person turns out to be Mossy. The air-fish returns with Mossy, who has the golden key in his hand.  The two children then embark on a journey to discover what the golden key will unlock.

This book is difficult to describe. It seems like a magical fairytale, but the imagery feels more intense than most children’s stories. The story is extremely mysterious and fantastical, and it seems to have profound spiritual significance. I sense that this book is intended to be an allegory, but I am not sure about its overall meaning. The main themes seem to relate to the journeys of life and death, as well as a hope in life after death. I found this book to be charming and delightful, even though I was baffled at times by its symbolism. I would recommend this book to anyone interested in reading a dreamlike story that is deeply mystical and imaginative.