The side door creaks open and you step inside, trading the rather dimly lit library for an even darker chamber. It takes a minute to find the light switch, and the single bulb sheds only a small glow into a vast corridor crammed with junk.
After coughing on the dust, you poke around a bit. Source material, indeed! Here are shelves with ancient scrolls ready to tear at the slightest excuse. And here are boxes filled with musty old books that are bound in leather. The writing is worn mostly off of the covers.
Stepping back into the center of the room, you try not to pay any attention to the wavering shadows in the corners. Finally, you reach a decision.