“You have done excellent work,” said Holmes scribbling a few words upon a half-sheet of paper. “We can do nothing legal without a warrant, and you can serve the cause best by taking this note down to the authorities and getting one. There may be some difficulty, but I should think that the sale of the jewellery should be sufficient. Lestrade will see to all details.”

“But they may murder her in the meanwhile. What could the coffin mean, and for whom could it be but for her?”

“We will do all that can be done, Mr. Green. Not a moment will be lost. Leave it in our hands. Now, Watson,” he added as our client hurried away, “he will set the regular forces on the move. We are, as usual, the irregulars, and we must take our own line of action. The situation strikes me as so desperate that the most extreme measures are justified. Not a moment is to be lost in getting to Poultney Square.

“Let us try to reconstruct the situation,” said he as we drove swiftly past the Houses of Parliament and over Westminster Bridge. “These villains have coaxed this unhappy lady to London, after first alienating her from her faithful maid. If she has written any letters they have been intercepted. Through some confederate they have engaged a furnished house. Once inside it, they have made her a prisoner, and they have become possessed of the valuable jewellery which has been their object from the first. Already they have begun to sell part of it, which seems safe enough to them, since they have no reason to think that anyone is interested in the lady’s fate. When she is released she will, of course, denounce them. Therefore, she must not be released. But they cannot keep her under lock and key forever. So murder is their only solution.”

“That seems very clear.”

“Now we will take another line of reasoning. When you follow two separate chains of thought, Watson, you will find some point of intersection which should approximate to the truth. We will start now, not from the lady but from the coffin and argue backward. That incident proves, I fear, beyond all doubt that the lady is dead. It points also to an orthodox burial with proper accompaniment of medical certificate and official sanction. Had the lady been obviously murdered, they would have buried her in a hole in the back garden. But here all is open and regular. What does that mean? Surely that they have done her to death in some way which has deceived the doctor and simulated a natural end - poisoning, perhaps. And yet how strange that they should ever let a doctor approach her unless he were a confederate, which is hardly a credible proposition.”

“Could they have forged a medical certificate?”

“Dangerous, Watson, very dangerous. No, I hardly see them doing that. Pull up, cabby! This is evidently the undertaker’s, for we have just passed the pawnbroker’s. Would you go in, Watson? Your appearance inspires confidence. Ask what hour the Poultney Square funeral takes place to-morrow.”

The woman in the shop answered me without hesitation that it was to be at eight o’clock in the morning. “You see, Watson, no mystery; everything above-board! In some way the legal forms have undoubtedly been complied with, and they think that they have little to fear. Well, there’s nothing for it now but a direct frontal attack. Are you armed?”

“My stick!”

“Well, well, we shall be strong enough. ‘Thrice is he armed who hath his quarrel just.’ We simply can’t afford to wait for the police or to keep within the four corners of the law. You can drive off, cabby. Now, Watson, we’ll just take our luck together, as we have occasionally done in the past.”

He had rung loudly at the door of a great dark house in the centre of Poultney Square. It was opened immediately, and the figure of a tall woman was outlined against the dim-lit hall.