He took up Ricardo’s paper and read it through again.

“Yes,” he said pleasantly.  “But the two questions which are most important, which alone can lead us to the truth—­how do they come to be omitted from your list, Mr. Ricardo?”

Hanaud put the question with his most serious air.  But Ricardo was none the less sensible of the raillery behind the solemn manner.  He flushed and made no answer.

“Still,” continued Hanaud, “here are undoubtedly some questions.  Let us consider them!  Who was the man who took a part in the crime?  Ah, if we only knew that, what a lot of trouble we should save ourselves!  Who was the woman?  What a good thing it would be to know that too!  How clearly, after all, Mr. Ricardo puts his finger on the important points!  What did actually happen in the salon?” And as he quoted that question the raillery died out of his voice.  He leaned his elbows on the table and bent forward.

“What did actually happen in that little pretty room, just twelve hours ago?” he repeated.  “When no sunlight blazed upon the lawn, and all the birds were still, and all the windows shuttered and the world dark, what happened?  What dreadful things happened?  We have not much to go upon.  Let us formulate what we know.  We start with this.  The murder was not the work of a moment.  It was planned with great care and cunning, and carried out to the letter of the plan.  There must be no noise, no violence.  On each side of the Villa Rose there are other villas; a few yards away the road runs past.  A scream, a cry, the noise of a struggle—­these sounds, or any one of them, might be fatal to success.  Thus the crime was planned; and there was no scream, there was no struggle.  Not a chair was broken, and only a chair upset.  Yes, there were brains behind that murder.  We know that.  But what do we know of the plan?  How far can we build it up?  Let us see.  First, there was an accomplice in the house—­perhaps two.”

“No!” cried Harry Wethermill.

Hanaud took no notice of the interruption.

“Secondly the woman came to the house with Mme. Dauvray and Mlle. Celie between nine and half-past nine.  Thirdly, the man came afterwards, but before eleven, set open the gate, and was admitted into the salon, unperceived by Mme. Dauvray.  That also we can safely assume.  But what happened in the salon?  Ah!  There is the question.”  Then he shrugged his shoulders and said with the note of raillery once more in his voice: 

“But why should we trouble our heads to puzzle out this mystery, since M. Ricardo knows?”

“I?” cried Ricardo in amazement.

“To be sure,” replied Hanaud calmly.  “For I look at another of your questions.  ‘What did the torn-up scrap of writing mean?’ and you add:  ‘Probably spirit-writing.’  Then there was a seance held last night in the little salon!  Is that so?”