six o'clock
That was Mr. Brunger 's discovery after examination of the window-latch where George 's knife had marked it , the sill where George 's boots had scratched it . Outside the great detective searched for footmarks -- they had been obliterated by heavy rainfall between the doing of the hideous deed and its discovery . Upon the principle of impressing his client , however , Mr. Brunger grovelled on the path with tape measure and note-book ; measured every pair of boots in the house ; measured the window ; measured the room ; in neat little packets tied up specimens of the gravel , specimens of the turf , specimens of hair from the Rose of Sharon 's coat , picked from her bed . It was six o'clock when he had concluded . By then George had returned ; the three held council in the study . Addressing Mr. Marrapit , Mr. Brunger tapped his note-book and his little packages . `` We shall track the culprit , never fear , Mr. Marrapit , '' he said .