Redania's Most Wanted - Novigrad
Quest Giver: King Radovid/Automatically accepted at the end of Get Junior
Other Requirements: N/A
This quest begins at the end of the Get Junior Story Quest. King Radovid asks Geralt for a favor which starts this quest.
Head on over to the quest marker in eastern Velen, you'll find a Signpost and a bunch of Witch Hunters outside of a cave entrance. Inspect the burned body or talk to the Witch Hunter with a fancy hat here for a scene. He'll give you a tile which you'll have to use on the wall shortly inside the dungeon to remove the purple barrier.
The dungeon itself is pretty straight forward, follow the quest's directions and the white dots on your compass. When you have to use Aard on the crystal, use your Witcher Senses to locate it. That makes the portals appear. Eventually you'll reach a Witch Hunter inside of the dungeon (pictured below) who has a crystal you're after. You can either use Delusion on him or beat him up in a fist fight to get the crystal.
In the same room with the Witch Hunter you'll have to use your Witcher Senses and find the Owl Feather on the ground, then you can go over to the quest marker and reveal the crystal you have to use Aard on. After going through the portal, inspect the feather in the other room with blood before going downstairs and taking out the Nekkars. Loot their corpses for a Power Cell which you can then use to open the next portal.
On the bottom floor of this dungeon you'll have to fight a boss, Ifrit. He's weak to Dimeritium Bombs as well as Elementa Oil. So long as you dodge most of his attacks the fight will be pretty easy for you.
When it's over head into the bedroom on the opposite side of the area you entered from. In here you will find two quest items, an agate as well as a Polished Crystal which is behind a megascope. The Polished Crystal will update your quest and send you to Triss back in Novigrad.
Don't forget to search the really large room you fought Ifrit in. You will find a few crafting recipes in there as well as many different treasure chests of goodies. When you're ready to leave take the portals back up to the top of the area and head back outside. Waiting for you outside will be the group of Witch Hunters and as you can probably guess, they want what you found.
Giving them your loot means you will get no further reward. I highly recommend you don't do this since this quest has a pretty big butterfly effect and connects to a lot of future quests. You want to keep the crystal which will mean you have to kill the Witch Hunters.
In the same room that you faught the Witch Hunters you'll find a wall that you can Aard down. Inside there is a chest with a Cat School Gear Crafting Diagram. It's one of the very rare recipes in Witcher 3. Now depending on what outcome of this quest you want determines what you should do next.
You have four options to choose from, you can show the crystal to Triss, Yennefer, return it to Radovid or lie to everyone. Note: In order to show this crystal to Triss you'll need to have not completed her chain of quests that begins with A Matter of Life and Death <Add link>.
Here are all the possible routes you can choose and what will happen if you do so. For my quest while writing this guide I gave the crystal to Triss and returned to Radovid empty handed. You don't get much of a Crowns reward for the quest anyway but this route still gets you EXP and keeps the crystal out of Radovid's hands.
Show it to Triss: She will reveal the hidden message to you and you have the option of letting her keep the crystal if you want or return it to Radovid.
Show it to Yennefer: You have a very short period of time during the game to show this item to Yennefer, you'll be holding onto it for most of the main story. Much like with Triss she reveals the hidden message too.
Give it to Radovid: He will give the crystal to a mage to decipher, you won't be told what the hidden message is but you'll receive a reward.
Lie: You won't receive any reward and will never discover the hidden message of the crystal.
When you're done making up your mind return to Radovid and speak with him to complete this quest officially. Redania's Most Wanted is one of the few side quests in this game that is directly tied into altering the game'sn ending. Completion of this quest is required to later receive the quest Reason of State <add link>; your actions in that quest will change the ending you receive in Witcher 3.