"Misery will fog the sight of the Clans." Somewhere in a mangrove forest, there are four clans. And at that somewhere, there's what they call a Moontree. And a gathering place. FogClan's medicine cats Berrygaze and Leopardpaw have been told to go on a journey. What they don't know is that a cat is waiting for there, longing for revenge. It's up to Duskleaf, Lionpaw, Leopardpaw, and Riverstar to figure out the mystery of who killed Berrygaze.