January 1150. Another attempt at peace has brought the kingdoms of Gwynedd and Powys together. Not everyone wants the conference to succeed, however, including King Madog of Powys, who happens to be a participant. So when the body of a woman turns up in an incriminating location, Queen Cristina is loath to involve anyone in the investigation but ... Gareth and Gwen. The Honorable Traitor is the fifteenth Gareth & Gwen Medieval Mystery.