The series that has sold over nine million copies continues with the first book in the new sixbook Omen of the Stars story arc. The Fourth Apprentice also includes the first adventure in the Warriors Adventure Game.

Lionpaw, Hollypaw, and Jaypaw—grandchildren of the Clan leader Firestar—are thriving as the newest ThunderClan apprentices. Yet with their new responsibilities come new experiences, new power... and secret dangers. Lionpaw makes a friend—and a discovery—that must be kept hidden; Jaypaw learns a secret that could benefit ThunderClan only by bringing harm to others; and Hollypaw knows something that could avert a battle, if only she could convince the rest of her Clan. Prophecy looms, ominous forces threaten to tear them apart, and each young cat discovers darkness: in the past, in the Clans—and in themselves.

There will be three, Kin of you kin.... Who hold the Power of the stars In their paws. A secret prophecy shapes the lives of Firestar's grandchildren, but only one of the three knows about it. Jaypaw is captivated by the power it promises, and he believes the key to that power may lie buried in the distant past — with the ancient cats who once walked these woods and now prowl through his dreams. His search for answers leads him toward the mountains — the home of the Tribe of Rushing Water. Lionpaw and Hollypaw feel drawn to the mountains too, for different reasons. But the mountains hide secrets as well as answers, and if the three cats find a way to get there, they may discover more than they ever expected.

Firestar's three grandchildren have learned of the powerful prophecy that foretells their destinies, and the responsibility of deciding the Clans' future weighs heavily on the three apprentices. But each secretly yearns for power: Lionpaw dreams of being undefeatable in battle, while Hollypaw longs to be a great leader and Jaypaw knows only he can see the true past and future for them all. Their strengths are tested when ThunderClan is suddenly attacked—and all four Clans are thrown into a battle unlike any the cats have ever seen. Then a dark shadow falls across the forest, and a mysterious stranger warns the Clans of more trouble to come. For the first time, it appears that StarClan does not hold the answers the cats need. All of a sudden, the warrior code is being tested. A crisis of faith threatens to tear the four Clans apart and destroy what the cats have built their lives upon...

The time has come for three kits of ThunderClan—Hollypaw, Jaypaw, and Lionpaw—to become apprentices. Grandchildren of the great leader Firestar, all three possess unusual power and talent. But dark secrets surround them, and a mysterious prophecy hints at trouble to come. The warrior code is in danger of being washed away by a river of blood, and all the young cats' strength will be needed if the Clans are to survive.

Fire alone can save our clan... Fireheart's traitorous enemy Tigerclaw has been vanquished and exiled from ThunderClan—but Fireheart can't shake the feeling that he's lurking out there in the forest, waiting for the chance to strike. That's not the only problem facing the young ThunderClan deputy in these blazing summer months, as he struggles to handle ominous omens, a disrespectful apprentice with a shocking secret, and a devastated Clan leader who is a shell of her former self. Meanwhile the forest gets hotter and hotter...and everyone braces for the coming storm...

ShadowClan has a dark new leader, but will he be satisfied with his power now — or does his desire for revenge burn even more strongly? Fireheart fears that there is a connection between the rise of Tigerstar and the terrible dreams that haunt his nights, murmuring of danger and death. Meanwhile, a mysterious and vicious threat unlike any other has invaded the forest, placing every cat's life in peril. Fireheart's beloved leader has turned her back on their warrior ancestors, and Fireheart can't help but wonder if she's right. Has StarClan abandoned them forever?

«ThunderClan's darkest hour is upon them, as Tigerstar's quest for power plunges all the Clans into the most terrible danger any cat has ever faced. In order to save his Clan and his friends, Fireheart must uncover the meaning of an ominous proclamation from StarClan: «Four will become two. Lion and tiger will meet in battle, and blood will rule the forest.» The time has come for prophecies to unfold, and for heroes to rise ...»

Fire alone can save our Clan... For generations, four Clans of wild cats have shared the forest according to the laws laid down by the powerful ancestors. But the warrior code is threatened, and the ThunderClan cats are in grave danger. The sinister ShadowClan grows stronger every day. Noble warriors are dying — and some deaths are more mysterious than others. In the midst of this turmoil appears an ordinary housecat named Rusty... Who may yet turn out to be the bravest warrior of them all.