Read it through once

I was modestly wondering whether my utmost ingenuity would have enabled me to say anything that would have amused him half as much as this imaginary pleasantry, when I was startled by a sudden click in the wall on one side of the chimney, and the ghostly tumbling open of a little wooden flap with “JOHN” upon it. The old man, following my eyes, cried with great triumph, “My son’s come home!” and we both went out to the drawbridge.