“There’s a gentleman downstairs, sir, who says he must see you instantly on most urgent business.  He seems to be in a rare twitter, sir—­”

Polton was proceeding to descriptive particulars, when a second and more hurried step became audible, and a strange voice addressed Thorndyke.

“I have come to beg your immediate assistance, sir; a most dreadful thing has happened.  A horrible murder has been committed.  Can you come with me now?”

“I will be with you almost immediately,” said Thorndyke.  “Is the victim quite dead?”

“Quite.  Cold and stiff.  The police think—­”

“Do the police know that you have come for me?” interrupted Thorndyke.

“Yes.  Nothing is to be done until you arrive.”

“Very well.  I will be ready in a few minutes.”

“And if you would wait downstairs, sir,” Polton added persuasively, “I could help the doctor to get ready.”

With this crafty appeal, he lured the intruder back to the sitting-room, and shortly after stole softly up the stairs with a small breakfast tray, the contents of which he deposited firmly in our respective rooms, with a few timely words on the folly of “undertaking murders on an empty stomach.”  Thorndyke and I had meanwhile clothed ourselves with a celerity known only to medical practitioners and quick-change artists, and in a few minutes descended the stairs together, calling in at the laboratory for a few appliances that Thorndyke usually took with him on a visit of investigation.

As we entered the sitting-room, our visitor, who was feverishly pacing up and down, seized his hat with a gasp of relief.  “You are ready to come?” he asked.  “My carriage is at the door;” and, without waiting for an answer, he hurried out, and rapidly preceded us down the stairs.

The carriage was a roomy brougham, which fortunately accommodated the three of us, and as soon as we had entered and shut the door, the coachman whipped up his horse and drove off at a smart trot.

“I had better give you some account of the circumstances, as we go,” said our agitated friend.  “In the first place, my name is Curtis, Henry Curtis; here is my card.  Ah! and here is another card, which I should have given you before.  My solicitor, Mr. Marchmont, was with me when I made this dreadful discovery, and he sent me to you.  He remained in the rooms to see that nothing is disturbed until you arrive.”

“That was wise of him,” said Thorndyke.  “But now tell us exactly what has occurred.”

“I will,” said Mr. Curtis.  “The murdered man was my brother-in-law, Alfred Hartridge, and I am sorry to say he was—­well, he was a bad man.  It grieves me to speak of him thus—­de mortuis, you know—­but, still, we must deal with the facts, even though they be painful.”

“Undoubtedly,” agreed Thorndyke.