Novigrad Dreaming - Novigrad
You receive this quest immediately after completing Pyres of Novigrad, the first story quest in Novigrad. Head over to the quest marker for this quest and you'll be thrown into a cutscene when you get close with a man by the name of Rudolf de Jonkheer. Head inside of the building after the cutscene and pillage everything on the first floor.
Go upstairs and into the bedroom for another cutscene, this one will give you two clues, attic and doll. You'll find the ladder that goes up into the attic in the other room, take it upstairs and pillage everything you come across. Aard open the blocked doorway and pick up the doll and picture of a crib. You'll find the crib on the second floor in the only other room connected to the bedroom.
Putting the doll into the crib will cause a cutscene, after which you'll want to examine the picture on the door to be clued into our next task. You'll find the furnace in the basement this time, which you can reach by a ladder going down nearby the stairwell on the first floor. There is also a cracked wall that you can Aard open in the basement, there's a few goodies in here that are worth collecting.
There are two possible outcomes that you can choose with this quest, tell Sarah to leave/force her out of the house or allow her to stay. Depending on the outcome you choose future quests/story lines will be altered. In particular, Sarah's story is tied closely with Johnny's. If you kick Sarah out of the house she eventually meets Johnny and you will get a scene with them together later in the game.
Note: Letting Sarah stay in this house will give you the future side quest Haunted House as well as credit towards helping monsters in Contract: Skellige's Most Wanted. Technically aside from Sarah being with Johnny, there is no reward for kicking her out of the house.
In order to kick Sarah out of the house you'll need to burn Burdock in the oven. To get the Burdock follow the white dots on your compass as they lead you through Novigrad to a Herbalist. Purchase the Burdock, return to the building and burn it. This will not only get Sarah to leave but also lift the curse/dreams on the person we need to speak to.
Speak to Corinne Tilly and your quest will update, sending you to another place in Novigrad where you have to speak with Corinne again. Much like before, follow the white dots on your compass for guidance. They will lead you right to Corinne. Keep this in mind for all future quests, many of them have these guiding white dots.