Contract: In Wolf's Clothing
Prerequisite: Begin "Nameless." | Suggested Level: 15
You can get this quest as a contract from the Larvik Notice Board, but it will also pop while doing "Nameless" for the main story. The ladies in Lofoten will tell you of Morkvarg, a cursed beast in Freya's Garden nearby.
For more information on Morkvarg, you can speak to Einar, who survived a confrontation with the beast. He's found at the docks near Larvik, just to the east. You won't learn much beyond the fact that lifting the curse on Morkvarg will be tough.
Now head to Freya's Garden. Take the steps up and around the locked door and drop in, then use your Witcher Senses to detect footprints. Follow these all the way to the rear of the garden. Enter the cave here to confront Morkvarg himself. After a scuffle, he'll fall to floor and beg you to lift the curse.
The first step to doing this is to find a special key. Use the sluices outside the cave to open the gate nearest the cave. Now you can dive into the water and find a second cave underneath; the key lies in here. With the key in hand, head to chapter house near the middle of the garden. Inside, you'll find Morkvarg's journal.
Read this to learn about your old pal Einar. Return to him with this new information, and he'll give you a cursed fang (make sure you learn how to use it before taking the violent path here). Return to Morkvarg with this - you'll have to battle him again - and use it to lift his curse for good. Alternatively, you can feed him werewolf meat for the same effect, which you can loot from wherever you first killed him. Once in human form, the can be killed for good or released, but either one will end the quest. If you didn't complete this quest via contract, you can still visit the issuer for a reward.
The Last Wish
Prerequisite: Complete "Nameless." | Suggested Level: 15
After the events of "Nameless," Yennefer will ask to meet you at the tavern on Larvik. Head there and speak to her to learn that she needs help tracking down a djinn. Follow her down to the docks to hop into the boat she's rented for the search.
Hop in and let Yen take you out to a search area in the water. She'll cast a spell to let you breath underwater, so dive in and swim down to find a cavern deep below the surface. Use your Witcher Senses to locate and examine the sunken hull of a ship. It won't be the right one, so return to Yen.
She'll sail to another spot. Same deal - dive in and use your Senses to find a skeleton and a buckler. Wrong ship. Swim back to Yen. She'll sail to the largest search area yet. Swim down to find a large crater under the surface, and use your Senses to locate a broken seal.
Return to Yen, and she'll use this seal to teleport you to a shipwreck on a mountaintop (no, really). After a little heart-to-heart, head to the wreck and use your Witcher Senses again to locate some drag marks below deck. You'll find a body and the other half of the seal nearby.
Meet Yennefer at the helm (I'd recommend throwing some elementa oil on your blade right about now). She'll repair the seal and summon the djinn: time for a battle. Take him down - it won't be too tough - and this quest will end after another intimate cut scene.
Prerequisite: None | Suggested Level: 25
There's a crypt southeast of Kaer Trolde Harbor. Head there to find two ladies by the entrance. They want to head inside, but according to them, the place is filled with ghosts. Head inside.
As you make your way through the crypt, you'll encounter wraiths. Fight your way to the final room to encounter a nightwraith. Use Yrden to make it vulnerable, then take it out. Return to the ladies outside to let them know the crypt is clear.
Prerequisite: None | Suggested Level: 24
At the northeastern edge of the main isle (look for a pair of boat icons on your map), you can find a group of pirates guarding some large chests. Take them out, then use your Witcher Senses to check the chests. You'll find a broken sword in one of them.
The chests belong to Clan Brokvar, so you'll need to sail to Svolarg on Spikeroog. Speak to the merchant there to return the sword for a reward.