Crookedstar's Promise is about Crookedstar, one of the leaders of River Clan. When he was a kit, Crookedstar made a promise to a StarClan cat that he would put his clan before everything else. In return, the StarClan cat, Mapleshade, promises to make him leader. Crookedkit didn't know how much that promise was going to cost him, his friends, family, and love. This books is great for cat lovers, but you have to read the Warriors series to understand it.