man, he commenced to apologize for having interrupted us at supper, but Keys waved aside his explanations and said abruptly. "You are a married man, sir, and very fond of your wife."

Wonderingly our visitor pleaded guilty to both indictments, and Keys resumed:

"Of course any one could tell that your wife has given you a Christmas present, a man with your intelligence would never buy a cigar like that, and only love for her would induce you to smoke it."

"Sir, I can see you are just the man to solve the mystery that is making my life a hideous nightmare, if I am fortunate enough to interest you in my case.

"My name is Humphrey Drake, and I am a country squire living in a peaceful village, and up to a week ago I was as placid as one of my own cows, but alas all is changed and I know not what dreadful fate is hanging over my head. I once read a wonderful book called 'The Sign of the Four,' (I am a modest man, so I blushed at this unconscious praise, you, dear reader, will know why), and now I fear that the terrible end of Bartholemew Sholto will be mine."

Mr. Drake turned very pale, whether from fear, or from the strong cigar, I do not know, but after a few minutes he recovered himself, and at Keys' request continued his story.

"Last week I had occasion to go to the stable immediately behind the house and on one of the walls saw in figures made with a piece of white chalk, this sign," and drawing his fountain pen from his pocket, he marked on our white table cloth

"I haven't been able to sleep since, and now I have come to you for help."

"Why did you visit the stable, Mr. Drake?" asked Keys.

"Well, lately the carriage and harness have not been properly cleaned, or the horse well groomed, and I went to speak to the stable-man about it."

Hastily consulting a time-table, Keys disappeared into his bed room, returning the next moment disguised as a stable-boy, even to a straw, which he was chewing assiduously.

"Whenson will put you up, Mr. Drake, and I will report to you at breakfast tomorrow morning. Meanwhile you can sleep in peace."

Coming down to breakfast the next morning, we found Keys seated by the fire reading the paper.

"Good morning, all is well, but breakfast first and business afterwards," he said.

It was not until our pipes were well alight that Keys deigned to satisfy our curiosity.

"The mystery was a very harmless one, Mr. Drake, as I expected it would be after the clue you gave me. I went round to the back of your house and looked in at the stable window, and there was the culprit, your young stable-man, with a laudable desire to improve his mind, though rather at the expense of his duty to you, I am afraid, was pouring over the arithmetic section of Barmsbirth's Universal Educator, and with a piece of white chalk was endeavoring to work out a simple sum on your stable wall, and, my dear sir, the answer to his sum, and the explanation of your mystery, is that two and two make four."

IV.

THE ADVENTURE OF THEOPHILUS BROWN

"'Tis not in mortals to command success," as the Immortal Bard hath it, and to illustrate the fact that my friend, Mr. Surelock Keys, really is mortal which one might easily doubt from