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 .