Precious Cargo is a secondary quest in White Orchard. Geralt finds a very upset merchant by the side of the road. He was hauling valuable goods to the Nilfgaardian camp when his horse panicked, veered off the road and dragged the cart into the foggy swamp. The horse got stuck in the mud and was eaten by the monsters that always seem to lurk in such places.
The merchant wants his cargo back, a mysterious box, and he would really prefer that Geralt did not ask what is inside. Getting it means wading into the swamp and dealing with the drowners around the wreck. Once Geralt has the box, he can hand it over without questions, or he can look into what the merchant is carrying. Curiosity has its price, and depending on the choice, the quest can end with a fight.