Gothic/Aid of the Magicians of Fire

You get this quest from Saturas as a subquest prior to Banishment from the Old Camp, so you actually can only get this quest late into the game, and you may only have access to it if you belong to the New Camp. There may be a way to trigger this quest early, by talking to Mordrag about his job as a courier after completing Thorus' quest but the main time you will gain this quest is after delivering all the Focus Stones to Saturas.

With all five Focus Stones and the Almanac, Saturas is prepared to blow the ore mound and destroy the ore mound, but he needs the help of the Magicians of Fire to recruit the necessary twelve. You are asked to go to the Old Camp and try and get the ears of the Fire Magicians; Saturas gives you a rune that will teleport the user to his chamber, for Corristo.

Before you leave the Old Camp, you can stop by Cronos and he can give you a letter for the Magicians of Fire, which is part of the ACTUAL QUEST. He will also give you a necklace that indicates you are a courier for the Magicians. Even if you join the New Camp, you probably won't be picking-up the Necklace until you get promoted into a Mercenary, which probably won't happen until this point in the game anyway. You can, of course, always ask Mordrag to "take you to the New Camp" (Thorus' Quest) and kill him in route for his necklace at an earlier point, but I don't recommend it and am not sure it will even work.

In any case, this quest is padded with journal entries that involve learning more about the collapse of the Old Mine, the securing of the Old Camp's gates, the murdering of the Magicians of Fire, and how Gomez plans to raid the Free Mine, and so forth. You will learn about these topics from Milton and Diego, respectively watching the North and South gates of the Old Camp.

When you report back to Saturas, the quest ends with a completion, even though you've done nothing, though your banishment from the Old Camp quest will continue for some time ...

Additionally, with the information you learn from Diego - initiating The Meeting - you can tell Lester about the murder of the Magicians of Fire.