One adorable blue dragon. A mysterious prophecy. Three new friends learning to trust each other. On the night of the full moon, Luna goes to the standing stones, hoping this time her mother will be there. Instead, she sees something incredible: a huge blue dragon, flying through the moonlit sky. This dragon is being chased by hunters, and Luna is heartbroken to see it fall from the sky. So when Luna finds the dragon's nest and rescues Spark, the last young dragon in the world, she must keep him safe and hidden - not easy with a growing dragon! Teaming up with her new friends, Tobi, the anxious prince, and Elodie, the librarian's daughter, the children must solve the mystery of why the king is so afraid of the dragons, before it's too late. Meanwhile, crops are failing, water is running out, and people have been forced to leave their homes. Soon a rebellion is brewing. When Luna and Spark are both finally reunited with their mothers, difficult choices must be made - for the sake of the whole kingdom.