The Renegade Merchant. The Gareth & Gwen Medieval Mysteries, #7

A pool of blood without a body leads Gareth & Gwen into trouble in Shrewsbury in The Renegade Merchant . March 1147. Determined to escape the gloom that has descended on Aber, Gareth and Gwen travel to Shrewsbury in an attempt to find answers about Rhun's death, about the whereabouts and plans of Prince Cadwaladr, and about Gwen's family ties to England. But when John Fletcher, now Deputy Sheriff of Shrewsbury, asks Gareth to help him investigate a pool of blood for which he has no body, Gareth can't refuse.
And when the investigation points to a conspiracy involving some of the leading citizens of Shrewsbury, Gwynedd's foremost investigators go looking for answers-and find that trouble isn't far behind. The Renegade Merchant is the seventh Gareth & Gwen Medieval Mystery. Complete Series reading order: The Good Knight, The Uninvited Guest, The Fourth Horseman, The Fallen Princess, The Unlikely Spy, The Lost Brother, The Renegade Merchant, The Unexpected Ally, The Worthy Soldier, The Favored Son, The Viking Prince, The Irish Bride, The Prince's Man, The Faithless Fool, The Honorable Traitor, The Admirable Physician, The Shattered King.
Also The Bard's Daughter (prequel novella).