The Carousel Adventure is a children's chapter adventure story featuring The Watch Hill Carousel, the oldest one of its kind in the United States. Also known as the Flying Horse Carousel, it consists of twenty wooden horses with real horse hair tails and manes. Suspended from rods with no platform, the horses seem to "fly" through the air as the carousel turns. On their annual summer visit to the carousel, Otto and Thora are excited to try for the brass ring that will earn a free ride. But when Otto retrieves the brass ring and decides to keep it, he has no way of knowing that its magical powers will take him and his twin sister, Thora, into the carousel panel paintings, where they will experience thrilling adventures.