A primary stat of 20 is suggested. If your main stat isn't high enough, you'll see the following message:
As you get near the library, you start thinking about all of the times you've been hurt because of libraries. Like the time that librarian broke your knees because you couldn't pay your overdue book fines, and the time that you tripped over a drawer that had been left open in the card catalog and got a black eye.
Maybe you should come back when you're a little tougher, so that you don't get hurt again.
(It is recommended that you have at least 20 <mainstat> to adventure here.)
You try to enter the Haunted Library, but the door is locked. I guess this particular information doesn't want to be free.
References
Information wants to be free is something of a slogan used by many (sometimes opposed) groups, including parts of the free content movement, the technological elite, anarchists, crackers, and parts of the sci-fi subculture.