Nor was it in the least clear what part, if any, she had played in the tragedy.  The facts still pointed as plainly to suicide as before her appearance.  Jeffrey’s repeated hints as to his intentions, and the very significant preparations that he had made, were enough to negative any idea of foul play.  And yet the woman’s presence in the chambers at that time, the secret manner of her arrival and her precautions against recognition, strongly suggested some kind of complicity in the dreadful event that followed.

But what complicity is possible in the case of suicide?  The woman might have furnished him with the syringe and the poison, but it would not have been necessary for her to go to his chambers for that purpose.  Vague ideas of persuasion and hypnotic suggestion floated through my brain; but the explanations did not fit the case and the hypnotic suggestion of crime is not very convincing to the medical mind.  Then I thought of blackmail in connection with some disgraceful secret; but though this was a more hopeful suggestion, it was not very probable, considering Jeffrey’s age and character.

And all these speculations failed to throw the faintest light on the main question:  “Who was this woman?”

A couple of days passed, during which Thorndyke made no further reference to the case.  He was, most of the time, away from home, though how he was engaged I had no idea.  What was rather more unusual was that Polton seemed to have deserted the laboratory and taken to outdoor pursuits.  I assumed that he had seized the opportunity of leaving me in charge, and I dimly surmised that he was acting as Thorndyke’s private inquiry agent, as he seemed to have done in the case of Samuel Wilkins.

On the evening of the second day Thorndyke came home in obviously good spirits, and his first proceedings aroused my expectant curiosity.  He went to a cupboard and brought forth a box of Trichinopoly cheroots.  Now the Trichinopoly cheroot was Thorndyke’s one dissipation, to be enjoyed only on rare and specially festive occasions; which, in practice, meant those occasions on which he had scored some important point or solved some unusually tough problem.  Wherefore I watched him with lively interest.

“It’s a pity that the ‘Trichy’ is such a poisonous beast,” he remarked, taking up one of the cheroots and sniffing at it delicately.  “There is no other cigar like it, to a really abandoned smoker.”  He laid the cigar back in the box and continued:  “I think I shall treat myself to one after dinner to celebrate the occasion.”

“What occasion?” I asked.

“The completion of the Blackmore case.  I am just going to write to Marchmont advising him to enter a caveat.”

“Do you mean to say that you have discovered a flaw in the will, after all?”

“A flaw!” he exclaimed.  “My dear Jervis, that second will is a forgery.”

I stared at him in amazement; for his assertion sounded like nothing more or less than arrant nonsense.