The questing cats return to a forest devastated by the Twolegs, where they must find a way to convince their Clans to leave in search of a new home, even though they have no idea where they are going.

Three young bears of different species--one black, one polar, and one grizzly--travel on a perilous quest to the Northern Lights, escorting a shape-shifting grizzly cub whose destiny will affect them all.

As Dovepaw, Jayfeather, and Lionblaze strive to understand and fulfill the prophecy that promises them great power, the cats of the Dark Forest begin to teach battle skills and techniques to different Clan cats through dreams.

As Hollypaw, Lionpaw, and Jaypaw, grandchildren of the legendary Firestar, continue their training to be warrior cats, each is haunted by a different internal struggle that could lead to trouble for all Clans.

When an ousider 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.

"As doubt rocks the forest, Firestar's three grandchildren are determined to convince the Clans that their faith in StarClan and the warrior code is more important than ever." --Back cover.

As Jayfeather, Lionblaze, and Dovepaw continue trying to understand the mysterious prophecy that binds them, Jayfeather receives a desperate plea for help from the Tribe of the Rushing Water.

A latest entry in the prequel story arc reveals new details about the history of the warrior cats and follows the efforts of Clear Sky to violently divide the territories of the forest cats in spite of Gray Wing's efforts to promote peace.

"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 the SkyClan returns to its rightful place among the warrior clans, not all the cats are convinced this is where the SkyClan belongs, leaving the clans' fate uncertain.