You've already been through the north door from the empty library, that led to the aquarium and lizards. The other door has a corridor that leads 20 feet, then turns south in the 30' section
After not hearing anything, the door opens onto a room 40' wide by 20' high. The room goes 10' to the left of the door section, and 20' to the right. There are no visible exits. The floor is littered with papers and pencils. The papers are of varying age,s from their colours