Miss Stoner did so, and Holmes, after a careful examination through the open window, endeavoured in every way to force the shutter open, but without success. There was no slit through which a knife could be passed to raise the bar. Then with his lens he tested the hinges, but they were of solid iron, built firmly into the massive masonry. “Hum!” said he, scratching his chin in some perplexity, “my theory certainly presents some difficulties. No one could pass these shutters if they were bolted. Well, we shall see if the inside throws any light upon the matter.”