At the age of almost eleven and almost thirteen years, it's finally time for Mosquito's and Jo's first riding lesson. At the neighbouring equestrian centre, the Spanish riding teacher Joseba is taking them on and teaching them to ride according to old tradition and skill. Besides their new four-legged friends Trudy and Kimba, they also get to know Lemony. Arguably the most beautiful horse in the whole world is also the scariest horse at the stable. Just as Jo and Mosquito start to get to know Lemony better, he disappears overnight, and Cloudlet takes over his place. Grief-stricken, Jo soon finds out that something is wrong with Cloudlet. But what? And where did Lemony disappear to? Read the whole story!