Heron is a rogue. He lives with his mother and two sisters on some land a little ways from the lake. One day, strange cats sneak into their home under the cover of night and kill Heron's mother and one of his sisters. They kidnap Heron and his surviving sister, Lily, and bring them into a shadowy pine forest.

   It turns out that the cats were of SkyClan. The Clan, who has the smallest territory, is starving and plaques by greencough. They stole the territory that used to be Heron's home, and forced Heron and his sister to train to be warriors. After their first battle, Lilypaw decides to become a medicine cat. But Heronpaw fights on. He hopes to destroy SkyClan, for taking cats that he loved.

   And he does. As he becomes a warrior under the name of Heronwing, he works to gain his Clanmates trust and admiration while killing cats secretly in the woods. Eventually, he is made deputy and kills the leader. Heronstar proceeds to kill almost every cat in SkyClan, and he and his sister flee after letting ShadowClan take back the territory.