"Did you ever notice the signals on the Great Northern Railway, Louis?" "Not particularly, Why?" "One winterly day, about the year when you and I were concerned in being born, the engine-driver of a Scotch express received the 'clear' from a signal near a little Huntingdon station called Abbots Ripton. He went on and crashed into a goods train and into the thick of the smash a down express mowed its way. Thirteen killed and the usual tale of injured. He was positive that the signal gave him a 'clear'; the signalman was equally confident that he had never pulled it off the 'danger.' Both were right, and yet the signal was in working order. As I said, it was a winterly day; it had been snowing hard and the snow froze and accumulated on the upper edge of the signal arm until its weight bore it down. That is a fact that no fiction writer dare have invented, but to this day every signal on the Great Northern pivots from the centre of the arm instead of from the end, in memory of that snowstorm." "That came out at the inquest, I presume?" said Mr. Carlyle. "We have had the Board of Trade inquiry and the inquest here and no explanation is forthcoming. Everything was in perfect order. It rests between the word of the signalman and the word of the engine-driver--not a jot of direct evidence either way. Which is right?" "That is what you are going to find out, Louis?" suggested Carrados. "It is what I am being paid for finding out," admitted Mr. Carlyle frankly. "But so far we are just where the inquest left it, and, between ourselves, I candidly can't see an inch in front of my face in the matter." "Nor can I," said the blind man, with a rather wry smile. "Never mind. The engine-driver is your client, of course?" "Yes," admitted Carlyle. "But how the deuce did you know?" "Let us say that your sympathies are enlisted on his behalf. The jury were inclined to exonerate the signalman, weren't they? What has the company done with your man?" "Both are suspended. Hutchins, the driver, hears that he may probably be given charge of a lavatory at one of the stations. He is a decent, bluff, short-spoken old chap, with his heart in his work. Just now you'll find him at his worst--bitter and suspicious. The thought of swabbing down a lavatory and taking pennies all day is poisoning him." "Naturally. Well, there we have honest Hutchins: taciturn, a little touchy perhaps, grown grey in the service of the company, and manifesting quite a bulldog-like devotion to his favourite 538." "Why, that actually was the number of his engine--how do you know it?" demanded Carlyle sharply. "It was mentioned two or three times at the inquest, Louis," replied Carrados mildly. "And you remembered--with no reason to?" "You can generally trust a blind man's memory, especially if he has taken the trouble to develop it."