Mia discovers a stallion in the Peppertree Forest. Hannah, Sofia, Sarah, and Lisa set out to find the animal, and they indeed discover the stallion, who is very shy and obviously injured. The friends manage to catch him and bring him to Lakeside. Of course, they start looking for his owner, but no one is reporting a missing horse. The girls are in the dark, but at least the horse is getting better day by day. One day, when they take him on an outing, they suddenly hear cries for help. Mia is in trouble and stuck in the swamp. How will the girls get her out of there? And then the stallion breaks free and runs straight into the swamp... Will the legend come true?.