The Witcher 3: Wild Hunt - Twisted Firestarter
Twisted Firestarter is a secondary quest in The Witcher 3: Wild Hunt which begins with by reading the notice board in White Orchard then talking to the blacksmith Willis. Willis will tell Geralt how someone burned down his forge. If Geralt says that he can find the arsonist, the blacksmith will offer gold and suggest checking for clues behind his house and the quest will begin.
Go behind the house to find the tracks and follow them, eventually leading Geralt down to the river. Follow the river bank north (left) to the other side of the bridge where the trail picks up again. Geralt will learn that the arsonist ran into a drowner and was wounded, at which point four drowners may attack. Once taken care of, continue to follow the trail back to the village and into a house.
Inside, Geralt finds the culprit, Napp, hiding in the back room with an injured hand. Napp will offer a bribe for Geralt to drop the whole thing. If Geralt refuses the bribe, he can either use Axii (extra XP) or brawl with Napp before making Napp stagger down to the blacksmith.
If Geralt turns in the arsonist, Willis will call over some soldiers, who will take Napp away, presumably to be hanged. The quest will complete, Geralt will receive his reward and a discount on the blacksmith's goods and services.
If Geralt accepts the bribe, Geralt will receive the same amount of crowns but less XP. Upon reporting failure to the blacksmith, the smith will still offer his services but will charge Geralt full price for it. Oddly, the smith's later conversation options match with Napp being turned in, even if he wasn't.