Blake was the only person in the house who was going to visit Lady Verinder. What actually followed upon that discovery, you remember, no doubt, quite as correctly as I do.'

I remembered that Franklin Blake had detected one of the spies, in the street--that he had, in consequence, advanced the time of his arrival in Yorkshire by some hours--and that (thanks to old Betteredge's excellent advice) he had lodged the Diamond in the bank at Frizinghall, before the Indians were so much as prepared to see him in the neighbourhood. All perfectly clear so far. But, the Indians being ignorant of the precaution thus taken, how was it that they had made no attempt on Lady Verinder's house (in which they must have supposed the Diamond to be) through the whole of the interval that elapsed before Rachel's birthday?

In putting this difficulty to Mr. Murthwaite, I thought it right to add that I had heard of the little boy, and the drop of ink, and the rest of it, and that any explanation based on the theory of clairvoyance was an explanation which would carry no conviction whatever with it, to my mind.

`Nor to mine either,' said Mr. Murthwaite. `The clairvoyance in this case is simply a development of the romantic side of the Indian character. It would be a refreshment and an encouragement to those men-- quite inconceivable, I grant you, to the English mind--to surround their wearisome and perilous errand in this country with a certain halo of the marvellous and the supernatural. Their boy is unquestionably a sensitive subject to the mesmeric influence--and, under that influence, he has no doubt reflected what was already in the mind of the person mesmerizing him. I have tested the theory of clairvoyance--and I have never found the manifestations get beyond that point. The Indians don't investigate the matter in this way; the Indians look upon their boy as a seer of things invisible to their eyes--and, I repeat, in that marvel they find the source of a new interest in the purpose that unites them. I only notice this as offering a curious view of human character, which must be quite new to you. We have nothing whatever to do with clairvoyance, or with mesmerism, or with anything else that is hard of belief to a practical man, in the inquiry that we are now pursuing. My object in following the Indian plot, step by step, is to trace results back, by rational means, to natural causes. Have I succeeded to your satisfaction so far?'

`Not a doubt of it, Mr. Murthwaite! I am waiting, however, with some anxiety, to hear the rational explanation of the difficulty which I have just had the honour of submitting to you.'

Mr. Murthwaite smiled. `It's the easiest difficulty to deal with of all,' he said. `Permit me to begin by admitting your statement of the case as a perfectly correct one. The Indians were undoubtedly not aware of what Mr. Franklin Blake had done with the Diamond--for we find them making their first mistake, on the first night of Mr. Blake's arrival at his aunt's house.'

`Their first mistake?' I repeated.

`Certainly! The mistake of allowing themselves to be surprised, lurking about the terrace at night, by Gabriel Betteredge. However, they had the merit of seeing for themselves that they had taken a false step--for, as you say, again, with plenty of time at their disposal, they never came near the house for weeks afterwards.'

`Why, Mr. Murthwaite? That's what I want to know! Why?'

`Because no Indian, Mr. Bruff, ever runs an unnecessary risk. The clause you drew in Colonel Herncastle's Will, informed them (didn't it?) that the Moonstone was to pass absolutely into Miss Verinder's possession on her birthday. Very well. Tell me which was the safest course for men in their position? To make their attempt on the Diamond while it was under the control of Mr. Franklin Blake, who had shown already that he could suspect and outwit them? Or to wait till the diamond was at the disposal of a young girl, who would innocently delight in wearing the magnificent jewel at every possible opportunity? Perhaps you want a proof that my theory is correct? Take the conduct of the Indians themselves as the proof. They appeared at the house, after waiting all these weeks, on Miss Verinder's birthday; and they were rewarded for the patient accuracy of their calculations by seeing the Moonstone in the bosom of her dress! When I heard the story of the Colonel and the Diamond, later in the evening, I felt so sure about