This Warriors: A Starless Clan Series, 5 Books Collection Set, River, Sky, Shadow, Thunder, Wind, by Erin Hunter
River (Book 1) — ISBN: 9780063050112
Sky (Book 2) — ISBN: 9780063050174
Shadow (Book 3) — ISBN: 9780063050228
Thunder (Book 4) — ISBN: 9780063050297
Wind (Book 5) — ISBN: 9780063050358

Publisher Marketing:
A thrilling new adventure begins in Erin Hunter's #1 bestselling Warriors series!
They have always lived by the code--but only change can keep the peace.
A new age is dawning on the warrior Clans. Now a new generation of warriors rises--one wrestling with the legacy of his great ancestor Firestar, one seeking to protect her troubled Clan, and one yearning to prove herself as a medicine cat--as leaders from all five Clans agree that the Warrior Code must be reformed.
But when tragedy strikes RiverClan, old fears will threaten the new peace... unless these three young cats can calm the coming storm.
This seventh epic Warriors series is full of action, intrigue, and adventure. This first book is the perfect introduction for new readers, while long-time fans will discover what unfolds after the events of The Broken Code.