When an outsider appears in the ThunderClan's midst, it drives the Clans further apart and as tension mounts they must decide who they can trust before it is too late.

Ravenpaw, a former ThunderClan apprentice, lives in peace outside the warrior Clans until five rogue cats from Twolegplace come to the barn where he lives and he must fight to save his new home.

"After countless moons of treachery, Tigerstar's Dark Forest apprentices are ready to lay siege upon the warrior Clans. As Jayfeather, Dovewing, and Lionblaze prepare to lead their Clanmates into battle, they await the arrival of the mysterious fourth warrior who is prophesied to help lead the Clans to glory."

After discovering that the destiny of the Clans is in their paws, Firestar's three grandchildren face turmoil as ThunderClan is attacked, war breaks out between the Clans, and a mysterious stranger warns of more trouble ahead.

Sent on a journey that could change the fate of all of the warrior clans, Hawking, deputy of SkyClan, must find the kin of Firestar, the cat who once brought their clan back from obscurity.

When Sasha feels betrayed by Tigerstar, she decides to leave the forest and search for her human family.

"The true Great Parent has finally risen and must unite all the animals of Bravelands to prevent an ancient evil from taking root"--

Firestar's grandchildren--Lionpaw, Hollypaw, and Jaypaw--progress in their training to become warrior cats and are drawn for different reasons to the mountains and the Tribe of Rushing Water.

"The traitor behind the sabotage and divisions within the Wild Pack has been unmasked, and one final confrontation will decide whether the Pack survives"--

When Firestar's grandchildren, Hollyleaf, Lionblaze, and Jay feather, finally discover who their true parents are, there are dire conseqyences for ThunderClan and the warrior code.