Contract: Swamp Thing is a side quest in Velen. A creature in Crookback Bog is terrorizing the nearby town. Go meet the man that posted the notice in the swamp. He says something in the fog is taking people and never letting them leave. You can haggle with him before entering the swamp. The base price is 249 and can go up to 339 crowns. When you settle on a price, head off into the swamp to find the mysterious fog.

Swamp Thing Walkthrough

Follow the marker on your mini map, fighting any Drowners you see along the way. You will arrive at the spooky fog soon enough. When you enter, Geralt will have a tough time breathing. Don’t worry about losing health. When you find the hut in the middle of the fog, you gain back any lost oxygen. Loot the hut and go off to a nearby rock face. There is an illusion blocking the cave entrance. Use the medallion from Keira Metz and go inside.

You’ll soon encounter a foglet. Quickly slay it then arm your blade with Necrophage Oil. It will help in the upcoming fight. Make sure to loot a nearby chest for new recipes and diagrams. When you’re all set, continue in the cave to meet Ignis Fatuus.

Monster Fight: Ignis Fatuus

Ignis Fatuous can be a tough fight, especially if you aren’t the advised level 12 for the contract. His hits take a lot of damage, so play it safe by dodging and using the Quen sign. The monster cannot leave the fog, so run off to regenerate health with a Swallow potion if you need to.

When fighting Ignis Fatuus, he will disappear into the fog often. Keep an eye on the denser clouds of fog to track him. He will also summon level 0 foggiest to distract you. Hit them once to get rid of them. Go in for attacks after Ignis Fatuus lunges and then dodge. Keep this up until he is dead. Using Thunderstruck potion can help speed up the fight as well.

When the “swamp thing” is dead, cut off his head as proof and leave the cave. Go back to the man who issued the contract and claim your reward.