As part of their investigation of the necromancers and the deaths of their two mages, Raminus Polus asks that the Hero head to Skingrad and retrieve a book from Count Janus Hassildor. Mercator is one of the two people the Hero may talk to if they wish to speak to the Count (the other being Hal-Liurz).
He lures them outside the City Wall and ambushes them with two other loyal necromancers, after which Mercator Hosidus will die during the battle. He was the second of Mannimarco's lieutenants to be killed.
- The word "mercator" is Latin for "merchant."
- Mercator's dialogue tones are different depending if the Hero arrived the mine earlier than him or not. If the Hero arrived there on time (after 2:00 am), he will simply say that they reached the mine on time and continue his dialogue in a calm tone. However, if the Hero reached there earlier than him (before 2:00), he will then say, "You're early, mage." and his following dialogues are much louder and bold, notably when he said, "So, you'll have to die!"