A Thief in ThunderClan" is a Warriors graphic novel where Brightheart, a ThunderClan warrior, investigates the disappearance of fresh-kill (prey) from the camp's fresh-kill pile. The story is set after the first series, "The Prophecies Begin," and before the second, "The New Prophecy," during the early days of Firestar's leadership. Brightheart, still recovering from a past trauma involving a dog attack, is suspicious of some clanmates and fears a betrayal. She teams up with her mate, Cloudtail, to solve the mystery, navigating trust issues and the challenge of leading during a time of peace after past conflicts.