"My dear Ned, I'm not a detective. A pretty face is no proof a woman is a saint. I told you before that there was generally something in the blood in those cases." As he stared at her, it seemed as though her words had indeed rushed back to his memory, and that they hit him hard. "People don't say that, do they?" he asked in a low voice. "Really, Ned, I don't know everything people say: but they are not likely to overlook much in such a case." He stood for a moment in silence. "She--I mean they've both got to be cleared!" he said, and strode out of the room. XIX THE EMPTY COMPARTMENT It was on this same evening that Superintendent Sutherland was almost rewarded for his vigilance by having something distinctly suspicious to report. As it happened, it proved a disappointing incident, but it gave the superintendent something to think about. He was going a few stations down the line to investigate a rumour of a suspicious person seen in that neighbourhood. It was a vague and improbable rumour and the superintendent was setting out merely as a matter of form, and to demonstrate his vigilance and almost abnormal sense of duty. Darkness had already fallen for an hour or two when he strode with dignified gait down the platform, exchanging a greeting with an acquaintance or two, till he came to the front carriage of the train. He threw open the door of the rear compartment, saw that it was empty, and was just going to enter when glancing over his shoulder he perceived his own cousin Mr. MacAlister upon the platform. Closing the door, he stepped down again and greeted him. Mr. MacAlister hailed him with even more than usual friendliness, and after a few polite preliminaries drew him insidiously towards the far side of the platform. An intelligent, inveterate and persevering curiosity was Mr. MacAlister's dominating characteristic, and as soon as he had got his distinguished kinsman out of earshot of the herd, he inquired in a hushed voice: "And what's doing aboot the murder noo, George?" The superintendent pursed his lips and shook his head. "Aye, man, yon's a proper puzzle," said he. "But you'll have gotten a guid idea whae's din it by noo, George?" said Mr. MacAlister persuasively. "Weel," admitted the superintendent, "we maybe have our notions, but there's no evidence yet, Robbie; that's the fair truth. As the fiscal says, there's no evidence." "I'd like fine to hae a crack wi' you aboot it, George," sighed Mr. MacAlister. "I may tell you I've notions of ma own; no bad notions either." "Well," said the superintendent, moving off, "I'd have enjoyed a crack myself if it wasna that I've got to be off by this train--" "Man!" cried his kinsman, "I'm for off by her mysel'! Come on, we'll hae our crack yet." The tickets had already been taken and the doors were closed as the two recrossed the platform. "This carriage is empty," said the superintendent, and threw open the door of the same compartment he had almost entered before.