The Secret of Glamis

In a certain drawing-room the other afternoon we were talking about some well-known superstitions and, among others, of that secret room in the castle of Glamis, which, Sir Walter Scott tells us, is known only to the earl of Strathmore, his heir apparent, and one other person in whom the earl may choose to confide. One of our party told us an amusing story concerning this secret chamber of Glamis. Once, when stopping at the castle in autumn, a curious and indiscreet visitor took advantage of the host’s absence to suggest a plan by which the whereabouts of the hidden chamber should be revealed. The castle was full and it was proposed that each guest should hasten to his or her room and hang his or her pillow out of the window, while one of visitor was told to mark off such window as displayed no white signal. In the middle of carrying out this pretty plan, the master of the castle returned unexpectedly and great was his wrath at this unseemly curiosity. Never had the owner of Glamis appeared in so towering a passion. The display of temper is hardly to be wondered at, for the Glamis secret is regarded with an extraordinary seriousness by the Strathmore family and when imparted to the heir has been known to fill him with gloom hard to dispel.–Sketch

Apparently, that there is a “Glamis Secret” is well-known, but there is still specualtion as to just what the secret is… Is it simply some secret rooms? Is it a deformed and hidden, but rightful, heir (now dead)? Did that young woman really get her tongue cut out? And what’s all this about being fortunate not knowing? And having to be male to be clued in?