She seated herself in the chair that Thorndyke placed for her, and continued in a brisk and business-like manner—­

“I must tell you who I am in order to explain my visit to you.  For the last six years I have lived with Mr. and Mrs. Hornby, although I am no relation to them.  I first came to the house as a sort of companion to Mrs. Hornby, though, as I was only fifteen at the time, I need hardly say that my duties were not very onerous; in fact, I think Mrs. Hornby took me because I was an orphan without the proper means of getting a livelihood, and she had no children of her own.

“Three years ago I came into a little fortune which rendered me independent; but I had been so happy with my kind friends that I asked to be allowed to remain with them, and there I have been ever since in the position of an adopted daughter.  Naturally, I have seen a great deal of their nephews, who spend a good part of their time at the house, and I need not tell you that the horrible charge against Reuben has fallen upon us like a thunderbolt.  Now, what I have come to say to you is this:  I do not believe that Reuben stole those diamonds.  It is entirely out of character with all my previous experience of him.  I am convinced that he is innocent, and I am prepared to back my opinion.”

“In what way?” asked Thorndyke.

“By supplying the sinews of war,” replied Miss Gibson.  “I understand that legal advice and assistance involves considerable expense.”

“I am afraid you are quite correctly informed,” said Thorndyke.

“Well, Reuben’s pecuniary resources are, I am sure, quite small, so it is necessary for his friends to support him, and I want you to promise me that nothing shall be left undone that might help to prove his innocence if I make myself responsible for any costs that he is unable to meet.  I should prefer, of course, not to appear in the matter, if it could be avoided.”

“Your friendship is of an eminently practical kind, Miss Gibson,” said my colleague, with a smile.  “As a matter of fact, the costs are no affair of mine.  If the occasion arose for the exercise of your generosity you would have to approach Mr. Reuben’s solicitor through the medium of your guardian, Mr. Hornby, and with the consent of the accused.  But I do not suppose the occasion will arise, although I am very glad you called, as you may be able to give us valuable assistance in other ways.  For example, you might answer one or two apparently impertinent questions.”

“I should not consider any question impertinent that you considered necessary to ask,” our visitor replied.

“Then,” said Thorndyke, “I will venture to inquire if any special relations exist between you and Mr. Reuben.”

“You look for the inevitable motive in a woman,” said Miss Gibson, laughing and flushing a little.  “No, there have been no tender passages between Reuben and me.  We are merely old and intimate friends; in fact, there is what I may call a tendency in another direction—­Walter Hornby.”