Once again return to the Guild, where you will get info on your new mission. This time you must search for the diary of lord Lucien. The localization of the diary is known to the lord's butler, who is hiding in one of the inns in Bowerstone. In exchange for the map which shows where the diary is, he demands 1000 golden coins. You don't really have a choice - you give him the required amount. Read the scroll and make your way to the Bower Lake. The shining trail will lead you right to the place where you must dig. Before you can take out your shovel, you will have to take care of a gigantic Forest Troll. To get rid of him, use magic or a ranged weapon and aim at the appendixes that will shine red after activating a spell/weapon.
Avoid the boulders that the monster throws at you. After you get rid of every single appendix, the troll will hit the ground, forming a wave of trembling earth that will be coming in your direction. When his health level lowers drastically, he'll double his attacks (he'll be throwing two boulders and forming two waves at once). After collecting the experience orbs, start digging in the place that your dog shows you.