The problem with tis one is that the mystery isn't excellent. The mystery is blindingly obvious from about page 30 and the contrivances to make it a mystery just seem tedious. But perhaps when it was written, the constant insinuation sof homosexuality were shocking enough to divert the teader's attention from the mystery.

Further, Cadfaeldoesn't have anything to do with solving the mystery, so what is the point of that?

Still rich in period detail, though, and that's mainly why you read them.