These three kittens are about to be ThunderClan apprentices. Hollypaw wants to be a medicine cat, and Jaypaw and Lionpaw will train to be warriors. However, Jaypaw is blind, and training to be a warrior will be hard for him. Eventually Hollypaw and Jaypaw switch roles after StarClan, the warrior ancestors, tell Jaypaw he needs to become a medicine cat. A few moons later, Lionpaw begins secretly meeting a WindClan apprentice, Heatherpaw while being trained by Tigerstar. Heatherpaw finds a set of secret tunnels under the ground and she and Lionpaw meet in them. Hollypaw finds out about this, and she and her friend Cinderpaw try to stop him from going to the tunnels. He eventually realizes that it is wrong to meet a cat from another clan, and breaks off the friendship. Then, three WindClan kittens get lost in the tunnels and Heatherpaw, Lionpaw, Hollypaw, Jaypaw, and Breezepaw have to save them.