Chitkree, the Lord Sage grows more serious as you mention the name Spernik. "Ah yes, a matter most grave. Spernik and his partner, Tibeem, were hired as scribes at the library about four months ago. They were skilled at their jobs, but not exceptional. Two days ago, they were caught sneaking out of my offices and when I questioned what they were doing there, they fled. I summoned the Black Fist and they gave chase. Spernik escaped, but Tibeem was caught and taken to Stojanow Gate...although not before slaying a Black Fist guard.". The Lord Sage sighs deeply, he's obviously troubled by the whole scenario. "I searched Spernik & Tibeem's room and found two rare tomes that had previously been stored in my personal library. When the books were taken back to be filed, two clever forgeries were already on the shelf in their place. Upon comparing the original tomes to the forged copies, each contained subtle factual inaccuracies; it seems that the two scribes intentionally changed the content of the forgeries. The books were found packed in a large haversack along with other equipment typically associated with an extended expedition; extra clothes, rope, food and water, etc.
I believe that Spernik may have stolen and stashed away other books, so if you plan to kill him they may be lost forever. I'm willing to offer 50 gp to bring the thief to justice and an additional 100 gp for the safe return of any other books or tomes that were stolen from the library."