November 1146. Gwynedd is at war with Ranulf, Earl of Chester, who seeks to gain a foothold in Wales against the day peace finally comes to England. On the eve of King Owain's counter-assault on Mold Castle, the body of a woman who bears a striking resemblance to Gwen is discovered buried in someone else's grave. Even in the midst of war, murder must be investigated, and it falls to Gareth and Gwen to bring the guilty to justice. When their investigation uncovers not only another body, but also treason at the highest levels of King Owain's court, Gareth and Gwen must come to terms with unprecedented treachery--and a villain whose crimes can never be forgiven. The Lost Brother is the sixth Gareth & Gwen Medieval Mystery.