“The Song of the Executioner,” originally aired February 25, 1995. Nostalgia and spoilers within.
So, Duncan is watching some monks sing the Kyrie. And someone is watching HIM watching monks. Mac used to hang out with these monks. So did the other guy, Kalas, who…killed the monk friend after the concert:/ And some other things start going wonky, too, like Anne’s patient/friend died and Joe gets framed for being a drug dealer. Whoops. Mac gets a ~message~ that the monk is dead. Mac immediately suspects Kalas because he used to behead monks leaving the monastery back in the day. He even thinks Kalas set up Anne by using his forgery skills. And since Mac doesn’t explain why he knows what he knows, they break up. Again.
Now that Mac knows who it is, he goes to confront Kalas at the opera hall. Where Kalas told Anne they’d be. And Duncan falls from overhead and breaks his neck. So Anne thinks he’s Dead dead. Oh, Anne. Mac decides to let her think he’s dead because he’s in Fairie Danger Land and Kalas is still out there. TIME FOR PARIS.