The Lost Omen (Warriors: Ultimate Stars, Crimson Skies Book #1)

The three Clans are recovering from an escalated case of greencough, one of which had left all cats in a state of disarray. With recently lost Clanmates and hackles raised, tensions are bound to explode, and NeedleClan deputy Lambcloud knows it. Already dealing with her own issues, she finds herself unable to fight her enemy when her leader, Loststar, declares war with SwiftClan over a miscommunication.

SwiftClan's deputy Gingerpool is struggling with her own problems, with both a kit and apprentice under her paw alongside a shattering secret. When she is newly appointed under Pepperstar, she demands great loyalty out of herself... But her weakness gives in at the sight of a young apprentice in desperate need of help, and she blames herself for Loststar's fury.

With a great divide and an overwhelming feeling of no choice, the two deputies form a peaceful alliance with one another amidst the chaos, and make a vow to save their two Clans from the incoming war, even if it costs them both their lives.