Novigrad, Closed City, Witcher 3: Wild Hunt Quest
1. Enter the Woman's Home and Get Rid of the Danger. / Defeat the Guards. Follow the Woman to Her House. When You Get Inside, You'll Realize There Are No...
1. Enter the woman's home and get rid of the danger. / Defeat the guards.
Follow the woman to her house. When you get inside, you'll realize there are no monsters there, only two witch hunters (11) who will attack you. When you kill them, Lussi will apologize for fooling you and tell you about the hidden treasure that should make it up to you. She'll give you one of the three keys you need to open the safe where the treasure is. You'll have to get the rest of the keys on your own.
Start by searching the bodies of the hunters. You'll find a warrant in them. Read it and you'll find out about the other people who should have the keys - Walter and Fritz.
Warrant
WANTED: Three bandits in possession of magic contraband. Objects are dangerous, banned, to be destroyed immediately.
Lussi, known as the Fox. Hiding on Temple Isle, near the bridge.
Fritz, hiding near the Crooked House.
Wallter, last seen in the Lacehalls, near the Putrid Grove.
Bandits are to be apprehended or, if they resist, killed where they stand.
2. Find the other partners mentioned in the note and look for keys. 1/3
Go to the place where Walter should be. When you get there, you'll see Walter banging on the door of one of the houses and two witch hunters (12) walking towards it.
If you kill the witch hunters before they attack Walter, he'll give you the key. If you don't make it and Walter dies, you'll find the key in his corpse.
Then go to Fritz's House. You'll find the body on the lower floor. It's Fritz, who's been dead for a quite some time.
Go up to the top floor and ignite the torch you find there. When you do that, the passage to the secret room will open.
On the table in the hidden room you will find the last of three keys.