“That widens the field to three,” said Poirot thoughtfully. “But Parker is the most likely. It is in my mind to try a little experiment with Parker. How say you, my friend, will you accompany me to Fernly?”

I acquiesced, and we set out at once. Poirot asked to see Miss Ackroyd, and presently Flora came to us.

“Mademoiselle Flora,” said Poirot, “I have to confide in you a little secret. I am not yet satisfied of the innocence of Parker. I propose to make a little experiment with your assistance. I want to reconstruct some of his actions on that night. But we must think of something to tell him⁠—ah! I have it. I wish to satisfy myself as to whether voices in the little lobby could have been heard outside on the terrace. Now, ring for Parker, if you will be so good.”

I did so, and presently the butler appeared, suave as ever.

“You rang, sir?”