Shadowy Hints

From: Jack
Description: Thanks to you we have all of my entourage’s rings, but we didn’t find any traitors among them. Martha suggests that we use the powers of the City. My mortal friend, bring some artifacts to appease it. May the City of Shadows shed some light on the identity of the traitor!
Completed: My mortal friend, Martha performed the ritual and the City revealed another ring. Oh, spirits... It cannot be?! This ring belonged to the Priest! But the Priest died, giving his life to hold back the Samhain Clock. Maybe this is a hint? Detective, look!