The Excalibur Murders
The "peace" of Camelot is shattered when first one squire, then his twin brother is murdered and both the legendary sword and the stone vanish. With jealousy, greed, and ambition running high, it will be a dangerous challenge for any sleuth to investigate the matter and there is no shortage of suspects. Fortunately, though Merlin has no magical powers, he is as brilliant as Sherlock and ably assisted by Nimue as he delves into the motives and clues presented to him and tries to keep Arthur from being the ultimate victim.
This is not your standard version of Camelot, though it is likely truer to the facts than the traditional. No love is lost between the King and his queen, but Lancelot is not nearly as noble either. Politics and sheer conflicting personalities make this a much more complicated land than the fairy tale images we usually see, but it's also a fascinating vision. I frankly loved this book and want to read more of the author and the series.