Warrior Cats: The Original Series is the first arc of the popular Warrior Cats series by Erin Hunter. The series focuses on housecat Rusty, who, tired of the easy life of a pet, decides to join ThunderClan, one of four warrior Clans who rule the forest neighboring his home. Rusty is dubbed Fireheart and sets out on a quest to unravel the secrets his Clanmates keep hidden in an effort to protect the forest from evil.