A chained dragon struggling to fly gives life to a visual illusion. As a result of the pre-tension, the dragon appears to hover in the air. The imaginary world and the dragon’s favorite character have been assembled into a model for assembly in order to bring the child into contact with a new engineering principle, prestressing. Following the illustrated manual, as well as the application, the child discovers all the techniques behind the way the tension works to create structural integrity so that the dragon looks like it is hovering!