She came to it, and as she stood looking again at the bent arm a sudden knowledge came to her as to the use to which the blood-stained handkerchief had been put: like so much else it seemed obvious directly the thought had come at all—the handkerchief had been used to wipe the arm and shoulder. She took it out and examined it again in connexion with the stains on the statuette; yes, there could be little doubt. The line of her mouth tightened: a passionate impulse, even if it culminated in a blow, was less horrible than these evidences of a cool-headed and deliberate purpose afterwards. She was struck with the inconsistencies which showed themselves here before her. The criminal could think to wipe the statuette, move the box, break the window, but he had never noticed that he had put his foot in the blood. Well, this was what she had often heard, that criminals nullified a dozen careful clevernesses by a single evident oversight: the agitated mind, she supposed, was too occupied in laying its deceptions to observe the most obvious realities. Her thoughts went again to the marks on the sill of the drawing-room window, which she had been able fully to see that morning for the first time; it had struck her then that they had seemed not merely indefinite, but partially obliterated. She saw at once now that her thought had been right; the ribs of dirt on the handkerchief, so out of place in the property of a conspicuously clean and respectable butler, had been made when the handkerchief had been hastily rubbed over the trodden sill. She could not be sure, but at least it seemed highly probable; and just as the stains raised the presumption of Fairlie’s handling of the statuette so did the dirt of his shutting of the window. She laid the handkerchief by, took the statuette carefully in her gloved hand by the clean arm and tipped it over; she was sure that the smooth polish of the pedestal would yield the best results and was afraid of testing the statuette itself in case she altered the appearance of the bloodstains. Carefully she sprinkled the fine flour over the front of the pedestal, brushed the surface very lightly, and then paused with shining eyes and a deep sigh, half satisfaction at the correctness of her conclusions and facility of her execution, half distress at the evidence of guilt before her. Clearly marked on the ebony towards each corner of the pedestal stood out the impressions of two large thumbs: the criminal after setting it down had evidently pressed it carefully back into its exact position.