“Well, this useless, clumsy maid at Louisa Wallace’s house—Dorcas. You implied that while you and she were standing together on the upstairs landing, you realized something important, but you didn’t say what it was that you realized.”

“That is true. I did not.”

“And this mysterious picture you drew and had delivered to Scotland Yard—what’s that all about? What was the picture of? And what is Stanley Beer supposed to do with it?”

“That, also, I did not tell you.” Poirot had the nerve to look apologetic, as if he had himself had no choice in the matter.

Foolishly, I persisted. “And why did you want to know how many times each and every Bloxham Hotel employee saw Harriet Sippel, Ida Gransbury and Richard Negus alive or dead? How is that pertinent to anything? You didn’t explain that either.”

“Poirot, he leaves the gaps all over the place!”

“Not to forget your earlier omissions. What, for instance, were the two most unusual features shared by the Bloxham murders and Jennie Hobbs’s outburst in Pleasant’s Coffee House? You said they had two highly unusual things in common.”

“Indeed I did. Mon ami, I do not tell you these things because I want to make of you a detective.”

“This case will make nothing of me but a miserable wretch, of no use to anyone,” I said, allowing my true feelings to have an outing for once in my life. “It’s the most maddening thing.”

I heard a noise that might or might not have been a knock at the drawing-room door. “Is somebody there?” I called out.

“Yes,” came Blanche Unsworth’s apprehensive voice from the hall. “I’m sorry to disturb you at this time, gentlemen, but there’s a lady to see Mr. Poirot. She says it can’t wait.”

“Show her in, madame.”

A few seconds later, I found myself face to face with the artist Nancy Ducane. Most men, I knew, would have thought her startlingly beautiful.

Poirot made the introductions with perfect courtesy.

“Thank you for seeing me.” Nancy Ducane’s swollen eyes suggested that she had done a fair amount of crying. She was wearing a dark green coat that looked expensive. “I feel dreadful, barging in on you like this. Please pardon the intrusion. I tried to persuade myself not to come, but . . . as you can see, I failed.”

“Please sit down, Mrs. Ducane,” said Poirot. “How did you find us?”

“With help from Scotland Yard, like a proper bona fide detective.” Nancy attempted a smile.

“Ah! Poirot, he chooses a house where he thinks no one will find him, and the police send the crowds to his door! No matter, madame. I am delighted to see you, if a little surprised.”