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The Witcher 3 - Swamp Thing: how to kill Ignis Fatuus

A step-by-step guide to completing the Swamp Thing Witcher Contract, from using the Eye of Nehaleni in the swamp to killing Ignius Fatuus.

To get this next Contract started, you'll need to hunt down a man who's harvesting away in the lands just to the west of the Orphan's Village in Crookback Bog. Your contact is based at a small outpost near the edge of the water, and his name is Leslav.

His problem, specifically, is that a monster is lurking around this region, and anyone who goes into the mists around here seems to vanish for good. Keep talking to Leslav to get more information about the creature's various forms, haggle for more money for the job if you wish, then get ready to track down the monster.

Head south, and go through the swampy mush. When you reach the target area, you'll need to keep walking towards the Peat Lodge. Look at the building with your Witcher Senses switched on and you'll find a corpse slumped over and a very badly decomposed chap not too much further away. Nasty.

Use the Eye of Nehaleni to expose the illusions

There's not much else to check out here, so head east this time towards the next area marked on your map. Watch out for nekkers as you travel, and kill any that are stupid enough to mess with you. You should next use your Witcher Senses to find the dead people that have been slashed by the beast.

Now use the Eye of Nehaleni to dispel the magical wall, then switch on your Witcher Senses again to find the tracks. Follow them south through this murky area, then keep your eyes peeled for a stinky corpse. Follow the smell south until you come to a pond with a foglet in it. Kill it, then look for the cave with a blocked off entrance. Use your Eye of Nehaleni once again to remove the illusory obstacle.

Go inside the cave but be ready to kill the foglets ahead of you. When you get up to go to the other side, you'll be back in the swamp. Deal with the ambush of slimy creatures, then head over to the pond near the exit where another pack of foglets need to be dealt with.


Our Witcher 3 walkthrough and guide can help you with the main story, including the Wandering in the Dark and Family Matters missions, and eventually, one of several Witcher 3 endings. There's plenty of side content, too, including Witcher 3 Contracts, White Orchard quests, Velen quests, Novigrad quests and Skellige Isles quests. Elsewhere, learn about the best Witcher 3 builds, the best Witcher 3 mods, how to make money in Witcher 3, find Places of Power locations, and learn how to do Witcher 3 crafting and Witcher 3 Alchemy And when you're done with all those - we can help you through expansions with our Hearts of Stone walkthrough and Blood and Wine walkthrough.


How to kill Ignis Fatuus with ease

Keep left and you'll soon walk right into the encounter with the main creature itself, Ignis Fatuus. You can make this fight a lot easier if you make use of your Quen Sign and put some Necrophage Oil onto your blade. You can also use a Moon Dust Bomb or two to keep things under control.

Once you've looted the corpse and cut its head off as a trophy, get back onto your horse and return to Leslav to get your reward.


- The next part of our Velen guide explains how to complete The Witcher 3 - Mystery of the Byways Murders.

- Return to the index page for more The Witcher 3 - Velen Secondary Quests and Contracts.

- To find all of our help for the game, take a look at our Witcher 3 walkthrough.