that a representative of a dictaphone company had called, the idea of a dictaphone took root in my mind. You heard what I said in this room not half an hour ago? They all agreed with my theory—but one vital fact seems to have escaped them. Granted that a dictaphone was being used by Mr. Ackroyd that night—why was no dictaphone found?”
“I never thought of that,” I said.
“We know that a dictaphone was supplied to Mr. Ackroyd. But no dictaphone has been found amongst his effects. So, if something was taken from the table—why should not that something be the dictaphone? But there were certain difficulties in the way. The attention of everyone was, of course, focused on the murdered man. I think anyone could have gone to the table unnoticed by the other people in the room. But a dictaphone has a certain bulk—it cannot be slipped casually into a pocket. There must have been a receptacle of some kind capable of holding it.
“You see where I am arriving? The figure of the murderer is taking shape. A person who was on the scene straightaway, but who might not have been if the crime had been discovered the following morning. A person carrying a receptacle into which the dictaphone might be fitted—”
I interrupted. “But why remove the dictaphone? What was the point?”
“You are like Mr. Raymond. You take it for granted that what was heard at nine-thirty was Mr. Ackroyd’s voice speaking into a dictaphone. But consider this useful invention for a little minute. You dictate into it, do you not? And at some later time a secretary or a typist turns it on, and the voice speaks again.”
“You mean—?” I gasped.
Poirot nodded. “Yes, I meant that. At nine-thirty Mr. Ackroyd was already dead . It was the dictaphone speaking—not the man.”