Warriors A Starless Clan Sky Book. #2. 

Discover more epic adventure in this second book in the Starless Clan arc. Disaster has struck at the heart of RiverClan, leaving its warriors and its new medicine cat apprentice
scrambling to protect their Clan—even if it means lying to the others. But at a time when the warrior code itself is shifting, no Clan is truly at peace… or truly safe.

Packed with action and intrigue, this seventh Warriors series is a perfect introduction for new readers, while long-time fans will be thrilled to discover what unfolds after the events of The Broken Code.