Mallow with a puzzled expression took the weapon in his hand and examined it closely.  “It is mine,” he admitted, “on the butts of my revolvers you will find I carve these notches.  I also did so on this bowie, which I bought in New York when I went on my last big-game shoot to the Rockies.  I marked my things in this way so that the other fellows should not use them by mistake.  I brought back this knife, and although it is not a pretty ornament, I fixed it up on the wall yonder.  I used it to cut up game.  But if you did not take it off the wall—­and I confess I never missed it until you drew my attention to the fact that it was missing—­where did you get it?”

Jennings scarcely knew what to say.  Cuthbert talked of the matter in so easy a manner that it was impossible to think he had killed Miss Loach.  Also he was not the sort of man to murder an inoffensive old woman, the more especially as he—­ on the face of it—­had no motive to commit so brutal an act, or to jeopardize his neck.  Struck by his friend’s silence, Mallow looked up suddenly.  Whether he read the truth in Jennings’ eyes or the recollection of Jennings’ profession brought the Crooked Lane crime into his mind, it is impossible to say.  But he suddenly grew pale and dropped the knife with a look of abhorrence.

“Yes,” said Jennings, in reply to his mute inquiry, “that is the knife that was used to stab Miss Loach.”

“This knife?” said Mallow, with a gasp, “but how the dickens,” he used a stronger word, “did my knife come to be used in that way?”

“I should like you to explain that,” said the detective icily.

“Good heavens, Jennings, you don’t think—­”

“What am I to think,” said Jennings coldly, “I swear I never suspected you, Mallow.  To own the truth, I don’t suspect you now, but for your own sake—­for your own safety, explain how that knife came to be in Miss Loach’s house.”

“I can’t say,” cried Cuthbert, vehemently, “really I can’t.  I swear I never missed it until you drew my attention to the blank left in the trophy of arms yonder.”  He flung himself into a seat, and passed his hand through his hair with a bewildered air.  “Surely, Jennings, you do not think me guilty of killing that poor wretch?”

Jennings stretched out his hand, which Mallow grasped.  “There is my answer,” said the detective, “of course I don’t suspect you.  The mere fact that you own the knife is yours shows me that you are innocent.  But the fact that this particular weapon was used reveals to me the strange behavior of Miss Saxon—­her motive, I mean.”

Cuthbert jumped up.  “What has Juliet to do with this?” he asked.

“I went to see her,” explained Jennings rapidly, “and was shown up to the attic of Rose Cottage by Mrs. Pill.  Miss Saxon was standing on a chair with her hand on the cornice.  I managed to place my hand in the same place—­it matters not how—­and there I found that.”