The four cat clans and their forest homes are being destroyed by two-legs(a.k.a. humans). Their only chance of survival lies with four chosen cats. These cats, accompanied by two others- Stormfur and Squirrelpaw- go on a mission to try and rescue the clans. While crossing over the mountains, they meet a Tribe of cats. The Tribe cats declare that Stormfur was sent to them to save them from Sharptooth- a mountain lion who has been picking off the Tribe cats one by one. In the end, one cat will not return home.