“I expect I shall have to,” answered Thorndyke.

“Then I shall just smarten the laboratory up a bit,” said Polton, who evidently appreciated the difference between the masculine and feminine view as to the proper appearance of working premises.

“And so Miss Gibson wanted to know our private views on the case?” said Thorndyke, when his voracity had become somewhat appeased.

“Yes,” I answered; and then I repeated our conversation as nearly as I could remember it.

“Your answer was very discreet and diplomatic,” Thorndyke remarked, “and it was very necessary that it should be, for it is essential that we show the backs of our cards to Scotland Yard; and if to Scotland Yard, then to the whole world.  We know what their trump card is and can arrange our play accordingly, so long as we do not show our hand.”

“You speak of the police as your antagonists; I noticed that at the ‘Yard’ this morning, and was surprised to find that they accepted the position.  But surely their business is to discover the actual offender, not to fix the crime on some particular person.”

“That would seem to be so,” replied Thorndyke, “but in practice it is otherwise.  When the police have made an arrest they work for a conviction.  If the man is innocent, that is his business, not theirs; it is for him to prove it.  The system is a pernicious one—­especially since the efficiency of a police officer is, in consequence, apt to be estimated by the number of convictions he has secured, and an inducement is thus held out to him to obtain a conviction, if possible; but it is of a piece with legislative procedure in general.  Lawyers are not engaged in academic discussions or in the pursuit of truth, but each is trying, by hook or by crook, to make out a particular case without regard to its actual truth or even to the lawyer’s own belief on the subject.  That is what produces so much friction between lawyers and scientific witnesses; neither can understand the point of view of the other.  But we must not sit over the table chattering like this; it has gone half-past seven, and Polton will be wanting to make this room presentable.”

“I notice you don’t use your office much,” I remarked.

“Hardly at all, excepting as a repository for documents and stationery.  It is very cheerless to talk in an office, and nearly all my business is transacted with solicitors and counsel who are known to me, so there is no need for such formalities.  All right, Polton; we shall be ready for you in five minutes.”

The Temple bell was striking eight as, at Thorndyke’s request, I threw open the iron-bound “oak”; and even as I did so the sound of footsteps came up from the stairs below.  I waited on the landing for our two visitors, and led them into the room.

“I am so glad to make your acquaintance,” said Mrs. Hornby, when I had done the honours of introduction; “I have heard so much about you from Juliet—­”