“Are you trying to make out that just because a chap’s father is a baronet, he never reads London Opinion?” enquired Anthony with some sarcasm.
“No, Anthony, I am not. You tend to miss my point. What I am very brilliantly endeavouring to convey to your moss-covered intelligence is that if Mr. Colin Woodthorpe, son of Sir Henry Woodthorpe, Bart., wanted to take a piece of literature with which to amuse himself while waiting for the other half of an appointment he’d probably take the Sporting Life, Punch, or a detective novel. That he might very nearly as well have taken London Opinion I readily admit, but only very nearly. What I’m considering, in fact, is the balance of probabilities. Now are you there?”
“But how do you know that the chap, whoever he was, did take it to amuse himself with while waiting for an appointment? How do you know there was an appointment at all?”
“I don’t, bandicoot,” Roger returned with exemplary patience. “But do you imagine (a) that he took it to read during the appointment, fearing lest he should be bored by the lady’s idle prattle; or (b) that he went down to that ledge all alone and crept into that cave for the sole purpose of reading London Opinion in the dark?”
“He might just as well have simply happened to have it with him, and chucked it away because he couldn’t be bothered to carry it home again.”
“He might,” Roger agreed at once; “but it isn’t nearly so likely. No, on the balance of probabilities I think we may assume that this man, probably not Woodthorpe, probably took London Opinion with him to read on the ledge while waiting for the other half of a probable appointment in that cave. He might have thrown it away then and there as soon as she turned up, but with that instinctive inhibition which most of us have against throwing something away with which we have not completely finished, he took it with him into the cave when the lady arrived and then, as you say, left it there because he couldn’t be bothered to take it home again—psychologically speaking, there is a large difference between throwing a thing away and leaving it behind. And we know the lady did turn up, dear little Anthony, because otherwise he wouldn’t have gone into the cave at all, but would have continued to sit outside where he could see to read. Are you with me?”
“Humph!” said Anthony.
“Now who was the other half of this man’s appointment?” Roger continued in argumentative tones. “Personally, I’m putting my money on Mrs. Vane. As far as friend Colin knew nobody but himself and Mrs. Vane had any inkling about that cave. He discovered it himself, he told us, about a year ago, and was at once struck with its suitability for the purpose to which he afterward put it. He was quite positive that he, at any rate, had told nobody else of its existence. To sum up then—if Colin is telling the truth all through, Mrs. Vane herself arranged an appointment with an unknown man belonging to the middle classes for some time since last Saturday morning, to discuss business of an obviously secret and confidential nature. And to stretch a point, we’ll add that that appointment resulted in her death, and that the unknown middle-class man is her murderer.—And how is all that,” Roger concluded with legitimate pride, “out of just finding a copy of London Opinion in that little cave, eh?”
“So now I should think you’d better go off and talk it all over with Moresby,” said Anthony hopefully.
“Anthony, you disgust me. Do you or do you not want to help me save your young woman from the gallows? No, don’t trouble to reply to that question; it’s a rhetorical one. You do. Very well, then. Continue, if you please, to sustain the part of idiot friend which you play so admirably.”