When their plans to spend spring break swimming and riding water slides comes to a crashing halt, Eli and Violet find themselves stuck at Grandma's. Thinking their week of fun is all but ruined, they are excited to meet Jack. A new neighbor and fast friend, Jack tells the siblings about something exciting: a cave in the woods with a carved dragon's head. Wanting to know more about it, and see the dragon themselves, the three head into the woods on what is sure to be an adventure of a lifetime.