Its identification was made easier by the fact that Vassalaro's name was engraved on the butt.

It was rather an ornate affair and in its earlier days had been silver plated; the handle was of mother-o'-pearl.
"Obviously the gift of one brigand to another," was T.X.'s comment.
Armed with this, his task would have been fairly easy, but when to this evidence he added a rough draft of the threatening letter which he had found amongst Vassalaro's belongings, and which had evidently been taken down at dictation, since some of the words were misspelt and had been corrected by another hand, the case was complete.
But what clinched the matter was the finding of a wad of that peculiar chemical paper, a number of sheets of which T.X.had ignited for the information of the Chief Commissioner and the Home Secretary by simply exposing them for a few seconds to the light of an electric lamp.
Instantly it had filled the Home Secretary's office with a pungent and most disagreeable smoke, for which he was heartily cursed by his superiors.

But it had rounded off the argument.
He looked at his watch.
"I wonder if it is too late to see Mrs.Lexman," he said.
"I don't think any hour would be too late," suggested Mansus.
"You shall come and chaperon me," said his superior.
But a disappointment awaited.

Mrs.Lexman was not in and neither the ringing at her electric bell nor vigorous applications to the knocker brought any response.

The hall porter of the flats where she lived was under the impression that Mrs.Lexman had gone out of town.