Speak to Witness Rastin and he will give you the quest. To save time, you can buy 5 sheets of parchment either from Artisan Daved or a materials trader before speaking to Symon. If you don't, he'll tell you to get the parchment first. When you have the parchment, give them to Symon and he'll give you the history. Take this to Rastin to complete the quest.