Deep in the heart of the forest, four Clans of warrior cats coexist in uneasy harmony - but uncertain times are upon them, and dangers threaten the precarious balance of the forest. Fireheart is a ThunderClan warrior now, but his troubles are far from over. The cats of rival RiverClan grow restless while WindClan is weak and faces threats from all sides. Now Fireheart faces not only imminent battle but betrayal from within his own Clan.

It is a time of peace between the warrior Clans, and all four are thriving. Then Firestar, leader of ThunderClan, discovers a terrible secret: The warrior ancestors of StarClan have lied to him. Firestar must embark on a perilous journey to right their wrong - and nothing will ever be the same again. 

For many moons, ThunderClan, ShadowClan, RiverClan, and WindClan have lived in peace in their territories around the lake. But now, they must decipher a mysterious prophecy - a message that will send one young medicine cat apprentice on a quest to determine the fate of all the warrior Clans. 

The Clans have finally arrived in their new home, and now, they must struggle to establish territories, learn hidden dangers, and find a new place to communicate with StarClan. But more than one cat is harboring sinister plans that could lead to violence and darkness, and as the warriors wait for a sign, they begin to realize the threats they face in the forest may not be as perilous as the threats they face from within. 

Long before Firestar left his kittypet home to join ThunderClan, a band of cats from the mountains set off on a dangerous journey in search of a new home....