Finding the box
Approach the merchant and inquire about his troubles to learn that his cart and goods have become stuck in a monster infested area of the bog. He requests that Geralt help him retrieve his lost merchandise, specifically a small box that was on the cart. The first step is to find where the cart left the road just a few steps away from the merchant himself. Use Witcher Senses to identify and then examine the cart tracks that lead off into the swamp, then follow them to the missing cart. Prepare to fight a few drowners before checking the cart.
Examine the cart to find that it is riddled with arrows, a big indicator that monsters didn't attack like the merchant said. Further examination of the horse's body (also with arrows) and a corpse nearby all indicate an attack that the merchant conveniently left out.
Nearby is the locked box, which is easy enough to find with Witcher Senses, and just happens to be covered in human blood.
Dealing with the merchant
Head back to the merchant, where you have two choices to make: give the box to him without mentioning his lie, or point out the lie. If you simply give him the box, he'll gladly pay Geralt for the help and then be on his way. If, however, you point out that he lied, he will poorly attempt to distract Geralt before escaping on horseback. Geralt must ride after him and attempt to knock him off his horse with either sword, crossbow, or bombs. He's not incredibly hard to catch if Geralt makes his horse gallop and takes shortcuts. Note: Do not let the bandit get too far away or the quest will fail.
If Geralt manages to knock him off his horse before he reaches the Temerian Insurgent Camp he will not have to contend with additional fighting. The merchant is revealed to be John Geermer, a private in a disbanded Temerian unit that has been part of a group conducting raids on Nilfgaardian supplies.
If he reaches the camp first Geralt will have to fight three bandits in addition to the liar Geralt was chasing in order to be victorious. Once Geralt knocked him off his horse or defeated the bandits in the camp the lying merchant will reveal his true identity.
After he's been caught, you have a few choices: let him go without the box, let him go with the box, or turn him in. After making your choice, the quest will complete.
- The merchant Geralt found standing by the side of the road in White Orchard was extremely distraught. He had been hauling some precious goods to the Nilfgaardian camp when his horse spooked and veered off the road, pulling the merchant's cart with it and dumping the whole works in the foggy swamp outside the camp. The poor horse became trapped in the muck and soon was devoured by the monsters who inevitably lurk in such places. The merchant was understandably afraid to go retrieve his goods, and thus asked the witcher to do it for him - in return for a sizable reward.
- If Geralt just returns the box without asking or investigating:
- The witcher found the merchant's priceless cargo and the grateful man repaid him in gold for his trouble. The contract had turned out to be a simple one, without any moral dilemmas or wrenching doubts about where the lesser evil lay, and to top it all off it ended with a satisfactory and immediately-paid reward - the witcher surely wished they could all be like that.
- If Geralt points out the merchant lied to him:
- Seemingly straightforward stories often turn out to be anything but. The witcher found the merchant's cart - and beside it signs of a malicious attack organized by human hands. It seemed the merchant had not told Geralt the whole truth. The confrontation that followed confirmed the witcher's suspicions - rather than stay to plead his innocence, the merchant immediately ran as fast as his legs could take him.
- If Geralt doesn't catch up to him:
- Geralt chased after the lying merchant but the scoundrel managed to give him the slip. He never did find out what really had happened out there in the murky swamps of White Orchard.
- If Geralt catches him...
- ...but refuses to give him the box:
- It turned out the "merchant" was no merchant at all, but a Temerian guerrilla. Though Geralt was skeptical about the man's chances in his partisan struggle against the mighty Nilfgaardian occupier, he decided to let him go...but kept the priceless object for himself. Perhaps he thought rewarding a cheat would not be the proper thing to do - or perhaps he was driven by a simple need for coin. It is not my place to judge, dear reader.
- ...and gives him the box:
- It turned out the "merchant" was no merchant at all, but a Temerian guerrilla. After Geralt heard the man explain his story and motives, he decided to let him go to continue his futile battle against the Nilfgaardian occupiers. Do not act so surprised, dear reader - witchers might be neutral by principle, but it was no secret where Geralt's sympathies lay in the struggle between the Northern Realms and the Nilfgaardian Empire.
- ...and turns him in to the Nilfgaardians:
- It turned out the "merchant" was no merchant at all, but a Temerian guerrilla. With his back against the wall, the soldier called on high ideals and Geralt's sense of patriotism in order to convince the witcher of the worthiness of his cause - but to no avail, for Geralt nevertheless handed him over to the nearest Nilfgaardian outpost. The witcher was clearly of the opinion that someone who acts like a bandit should end like a bandit, no matter how lofty his declared motives.
- Find the little box the merchant mentioned using your Witcher Senses.
- Use your Witcher Senses to find where the cart left the road.
- Find the cart.
- Look around the cart for evidence about the attack using your Witcher Senses.
- Return the box to the merchant.
- Chase down the merchant. (only shows if Geralt pointed out the lie)
- Knock the merchant off his horse. (only shows if Geralt pointed out the lie)
- If you give the box to the merchant without seeing through his lies he will get on his horse and immediately ride to the bandit camp that he would have fled to if you were to see through his lies. There will be no bandits there however.