“The absence of the latter means nothing, though its presence may mean everything,” said Holmes. “Unless the powder from a badly fitting cartridge happens to spurt backward, one may fire many shots without leaving a sign. I would suggest that Mr. Cubitt’s body may now be removed. I suppose, Doctor, you have not recovered the bullet which wounded the lady?”

“A serious operation will be necessary before that can be done. But there are still four cartridges in the revolver. Two have been fired and two wounds inflicted, so that each bullet can be accounted for.”

“So it would seem,” said Holmes. “Perhaps you can account also for the bullet which has so obviously struck the edge of the window?”

He had turned suddenly, and his long, thin finger was pointing to a hole which had been drilled right through the lower window-sash, about an inch above the bottom.

“By George!” cried the inspector. “How ever did you see that?”

“Because I looked for it.”

“Wonderful!” said the country doctor. “You are certainly right, sir. Then a third shot has been fired, and therefore a third person must have been present. But who could that have been, and how could he have got away?”

“That is the problem which we are now about to solve,” said Sherlock Holmes. “You remember, Inspector Martin, when when the servants said that on leaving their room they were at once conscious of a smell of powder, I remarked that the point was an extremely important one?”

“Yes, sir; but I confess I did not quite follow you.”

“It suggested that at the time of the firing, the window as well as the door of the room had been open. Otherwise the fumes of powder could not have been blown so rapidly through the house. A draught in the room was necessary for that. Both door and window were only open for a very short time, however.”

“How do you prove that?”

“Because the candle was not guttered.”

“Capital!” cried the inspector. “Capital!”

“Feeling sure that the window had been open at the time of the tragedy, I conceived that there might have been a third person in the affair, who stood outside this opening and fired through it. Any shot directed at this person might hit the sash. I looked, and there, sure enough, was the bullet mark!”

“But how came the window to be shut and fastened?”

“The woman’s first instinct would be to shut and fasten the window. But, halloa! what is this?”

It was a lady’s hand-bag which stood upon the study table — a trim little handbag of crocodile-skin and silver. Holmes opened it and turned the contents out. There were twenty fifty-pound notes of the Bank of England, held together by an india-rubber band — nothing else.

“This must be preserved, for it will figure in the trial,” said Holmes, as he handed the bag with its contents to the inspector. “It is now necessary that we should try to throw some light upon this third bullet, which has clearly, from the splintering of the wood, been fired from inside the room. I should like to see Mrs. King, the cook, again. You said, Mrs. King, that you were awakened by a loud explosion. When you said that, did you mean that it seemed to you to be louder than the second one?”

He knew too well what was about to happen in the house of the poor doctor to feel any desire to look into it. He did not even get up when his only servant -- who envied the lot of the servants of Cornelius just as bitterly as Boxtel did that of their master -- entered his bedroom. He said to the man, --

"I shall not get up to-day, I am ill."

About nine o'clock he heard a great noise in the street which made him tremble, at this moment he was paler than a real invalid, and shook more violently than a man in the height of fever.

His servant entered the room; Boxtel hid himself under the counterpane.

"Oh, sir!" cried the servant, not without some inkling that, whilst deploring the mishap which had befallen Van Baerle, he was announcing agreeable news to his master, -- "oh, sir! you do not know, then, what is happening at this moment?"

"How can I know it?" answered Boxtel, with an almost unintelligible voice.

"Well, Mynheer Boxtel, at this moment your neighbour Cornelius van Baerle is arrested for high treason."

"Nonsense!" Boxtel muttered, with a faltering voice; "the thing is impossible."

"Faith, sir, at any rate that's what people say; and, besides, I have seen Judge van Spennen with the archers entering the house."

"Well, if you have seen it with your own eyes, that's a different case altogether."

"At all events," said the servant, "I shall go and inquire once more. Be you quiet, sir, I shall let you know all about it."

Boxtel contented himself with signifying his approval of the zeal of his servant by dumb show.

The man went out, and returned in half an hour.

"Oh, sir, all that I told you is indeed quite true."

"How so?"

"Mynheer van Baerle is arrested, and has been put into a carriage, and they are driving him to the Hague."

"To the Hague!"

"Yes, to the Hague, and if what people say is true, it won't do him much good."

"And what do they say?" Boxtel asked.

"Faith, sir, they say -- but it is not quite sure -- that by this hour the burghers must be murdering Mynheer Cornelius and Mynheer John de Witt."

"Oh," muttered, or rather growled Boxtel, closing his eyes from the dreadful picture which presented itself to his imagination.

"Why, to be sure," said the servant to himself, whilst leaving the room, "Mynheer Isaac Boxtel must be very sick not to have jumped from his bed on hearing such good news."

And, in reality, Isaac Boxtel was very sick, like a man who has murdered another.

But he had murdered his man with a double object; the first was attained, the second was still to be attained.

Night closed in. It was the night which Boxtel had looked forward to.

As soon as it was dark he got up.

He then climbed into his sycamore.

He had calculated correctly; no one thought of keeping watch over the garden; the house and the servants were all in the utmost confusion.

He heard the clock strike -- ten, eleven, twelve.

At midnight, with a beating heart, trembling hands, and a livid countenance, he descended from the tree, took a ladder, leaned it against the wall, mounted it to the last step but one, and listened.