These were the main points of the servants' evidence. In answer to Inspector Martin they were clear that every door was fastened upon the inside, and that no one could have escaped from the house. In answer to Holmes they both remembered that they were conscious of the smell of powder from the moment that they ran out of their rooms upon the top floor. "I commend that fact very carefully to your attention," said Holmes to his professional colleague. "And now I think that we are in a position to undertake a thorough examination of the room."
The study proved to be a small chamber, lined on three sides with books, and with a writing-table facing an ordinary window, which looked out upon the garden. Our first attention was given to the body of the unfortunate squire, whose huge frame lay stretched across the room. His disordered dress showed that he had been hastily aroused from sleep. The bullet had been fired at him from the front, and had remained in his body after penetrating the heart. His death had certainly been instantaneous and painless. There was no powder-marking either upon his dressing-gown or on his hands. According to the country surgeon the lady had stains upon her face, but none upon her hand.
"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 backwards, 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 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 has 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!"