The Sergeant obeyed, using his handkerchief. Hemingway took them, and closely scrutinised them. It was plain that the sheaths at least had not been taken down recently, since dust clung to the undersides, and a few wispy cobwebs on the wall were revealed by their removal. Indeed, the Sergeant, descending from his perch, and studying the knives, gave it as his opinion that neither had been handled.
"Take another look," advised Hemingway. "Notice anything about the hilts?"
The Sergeant glanced quickly at him, and then once more bent over the weapons. As Hemingway held them up the dust on them was clearly visible. Each sheath, where it had lain against the wall, was thinly coated with dust, and so was one hilt. The other hilt had no speck of dust on it, on either side.
The Sergeant drew in his breath. "My lord, Chief, you're quick!" he said respectfully.
"You can put this one back," said Hemingway, unmoved by the compliment, and handing him the knife with the dusty hilt. "It hasn't been touched. But this little fellow has been drawn out of its sheath very recently, or I'm a Dutchman!" He held it up to the light, closely inspecting the hilt for finger-prints. No smudge on its polished surface was visible to the naked eye, and he added disgustedly: "What's more, when the experts get on to it, they'll find that it's been carefully wiped. However, we won't take any chances. Lend me that handkerchief of yours, will you?"
The Sergeant gave it to him. Carefully grasping the base of the hilt between his finger and thumb through the folds of the linen, Hemingway drew the knife from the sheath. It slid easily, a thin blade which revealed a slight stain close to the hilt. The Sergeant pointed a finger at this, and Hemingway nodded. "Overlooked that, didn't he? Well, I fancy we have here the weapon that killed Nathaniel Herriard." Perceiving a look of elation on his subordinate's face, he added dampingly: "Not that it's likely to help us, but it's nice to know."
"I don't see why it shouldn't help us," objected Ware. "It proves the murder was an inside job, anyway."
"Well, if that's your idea of help, it isn't mine," said Hemingway. "Of course it was an inside job! And a nice, high-class bit of work too! There won't be any fingerprints on this. You have to hand it to our unknown friend. Thinks of everything. He chooses a weapon which nine people out of ten would stare at every day of their lives without attaching any importance to. He chooses a time when the house is full of visitors who all have their reasons for wanting old Herriard out of the way; and seizes the moment when everyone's dressing for dinner to stab his host, and restore the knife at his leisure. It's an education to have to do with this bird."
The Sergeant gazed meditatively up at the wall over the fireplace. "Yes, and what's more, he might have taken the knife at any time," he said. "There's no sign he took the sheath as well."
"There's every sign he didn't."