Go to the basement under Elise's Bedroom. Use the lamp to open the wall. Billy should spawn as you enter. Kill him. ( 49, 0, 75 ) /waypoint 49, 0, 75
Go to the Game Room ( 32, 0, 59 ) /waypoint 32, 0, 59 and walk into the room, Billy will now auto-spawn when someone is on this step of the quest.
Go to the the Chapel ( -36, 0, 53 ) /waypoint -36, 0, 53. Again Billy auto-spawns when you walk into the room now.
Go to the Library ( -27, 14, 59 ) /waypoint -27, 14, 59. Read a book in the secret area behind the bookcase. It's the book leaning against the coffin at ( -23, 13, 29 ) /waypoint -23, 13, 29. It's written by Everling and he says, "the dolls I need always come to me in the courtyard".
Go down to the courtyard by the entrance. (try the center of the courtyard) A NPC version of Billy will spawn automatically. Hail him. The dialogue gives you two options, either give him 5g or yell at him. Give him gold.
Go to the jail and hail the froglok ghoul assassin ( -24, 0, 29 ) /waypoint -24, 0, 29. He tells you to get something to soothe his soul.
Go to the library and read the directions on a scroll ( -22, 13, 31 ) /waypoint -22, 13, 31 in the hidden area; on the standing bowl not the desk. (see sub-step 3 before leaving the library)
Kill 21 Nyth dolls. There are only 30 dolls in the castle and they do not respawn, so make sure you don’t kill them before you need them.
Note:There are 4 nyth doll encounters in the zone: a group of 3 pop when you walk over the bed in the northwest tower where Crysta's Handmaiden is; one probably aggros when you get the quest starter; a group of 8 in a group at a dead-end on the floor with the library with a captain at the door; the largest group is before the door to Lord Everling. if you manage to kill just the group when you get the starter you save to get them all in 1 run
Fiendish blood: This is a triggered 35^^^ Lamia (Archfiend Ivariai) which will probably aggro you as soon as you leave the library or shortly thereafter. So be ready.
Note: the swine are placeholders for the Swine Lord
Go back to the froglok assassin and speak to him. He depops at the end of quest conversation.
Note: If everyone finishes at the same time you're okay, if not just wait ten minutes for him to repop. So try to time your hailing so that you all do it at once. The update comes when you click the dialog that says "How will I know where the mask is?". For multiple people to get the update, do not click any further.
Kill Lord Everling.(Note: If you fail to kill Everling and respawn at the entrance, you will not be able to get back to him: the door locks. You will have to wait until you can enter the zone again to finish the quest.) See the quest The Everling Lockets for details on accessing him.
Inspect the chest that's in the closet off of Everling's laboratory ( 224, -17, 28 ) /waypoint 224, -17, 28 to receive your reward. (Note: you do not need to kill Lord Everling to open the chest, so if he's not up because you killed him for another quest just go to the chest)