"What's in here?" he asked, tapping the safe.

"My stepfather's business papers."

"Oh! you have seen inside, then?"

"Only once, some years ago. I remember that it was full of papers."

"There isn't a cat in it, for example?"

"No. What a strange idea!"

"Well, look at this!" He took up a small saucer of milk which stood on the top of it.

"No; we don't keep a cat. But there is a cheetah and a baboon."

"Ah, yes, of course! Well, a cheetah is just a big cat, and yet a saucer of milk does not go very far in satisfying its wants, I daresay. There is one point which I should wish to determine." He squatted down in front of the wooden chair and examined the seat of it with the greatest attention.

"Thank you. That is quite settled," said he, rising and putting his lens in his pocket. "Hullo! Here is something interesting!"

The object which had caught his eye was a small dog lash hung on one corner of the bed. The lash, however, was curled upon itself and tied so as to make a loop of whipcord.

"What do you make of that, Watson?"

"It's a common enough lash. But I don't know why it should be tied."

"That is not quite so common, is it? Ah, me! it's a wicked world, and when a clever man turns his brains to crime it is the worst of all. I think that I have seen enough now, Miss Stoner, and with your permission we shall walk out upon the lawn."

I had never seen my friend's face so grim or his brow so dark as it was when we turned from the scene of this investigation. We had walked several times up and down the lawn, neither Miss Stoner nor myself liking to break in upon his thoughts before he roused himself from his reverie.

"It is very essential, Miss Stoner," said he, "that you should absolutely follow my advice in every respect."

"I shall most certainly do so."