The Library Room (2 points)
You come to a long room with ten bookshelves around the walls, each labelled for a different sub-field of natural history: marine life, botany, palaeontology, avians, mammals, geology, physical science, chemistry, herpetology and medicine. There is a table in the middle of the room, turkish-style rugs covering the floor, a desk and chair in the middle, and a pen and paper on the desk. The shelves are full of old looking books; the ceiling is decorated with an attractive painting of a flock of emus. There are no visible doors, except the one you came in through.
On the paper has been written:
"Welcome stranger! One of the bookcases is the hidden door to continue your journey: simply select the third book from the left on the middle shelf, and the revolving wall will turn, swivelling the bookcase and floor section you're standing on around and taking you onwards. One slight issue, though: if you try selecting from the wrong bookcase, a hidden panel in the ceiling will pour boiling tar on you, almost certainly killing you. Don't worry, safety precautions have been put in place to ensure your demise in this manner will not risk damage to any of the rare books in our collection. Good luck!"
How will you escape?