Gerald Hughes longs for something magical to happen in his life. His mother is grieving for the loss of his father in the Second World War; he feels alone and is without true friendship and happiness.
When Gerald discovers an unusual caterpillar hidden amongst the undergrowth in the fields which surround his home, he instantly senses the creature's magical qualities and embarks on a journey through 15 days of summer, knowing that from this moment on, his life will never be the same again.
Can this magical creature help Gerald finally feel happiness in his heart? Will what he discovers change his feelings about his family forever and will Gerald ever find out the magical caterpillar's purpose?