Availability: After you reach Old Town
Location: The University
Rewards: 5,000 Survivor XP
Difficulty: Medium
Talk to Fidan, in the Old Town university library. He lets you know about a skilled gunsmith in the area. He wants you to find the man, and it might be useful for you to do so. Look on the northeastern side of town. There is a penthouse apartment where Rupert is said to reside. Climb up there and search the building.
Rupert is downstairs, in a day care center. Talk to him to find out about the place. The conversation chains into “Health Potion” (another quest), and then later gives you access to several more quests here as well. It’s a very lucrative chain of events.