Contract: Swamp Thing is a contract 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. When you settle on a price, head off into the swamp to find the mysterious fog.