It now seemed likely that Samuel Kidd had been within inches of the murderer last night. A frightful-looking lady. I shivered.

“This woman that you saw,” said Poirot, “did she have fair hair and a brown hat and coat?”

He was, of course, thinking of Jennie. I still believed there was no link, but I could see Poirot’s reasoning: Jennie had been running around London last night in a state of great agitation and so had this other lady. It was just about possible they were one and the same person.

“No, sir. She had a hat on but it were pale blue, and her hair were dark. Curled and dark.”

“How old was she?”

“Wouldn’t like to guess a lady’s age, sir. Between young and old, I’d say.”

“Apart from the blue hat, what was she wearing?”

“Can’t say I took that in, sir. I was too busy looking at her face when I could.”

“Was she pretty?” I asked.

“Yes, but I wasn’t looking for that reason, sir. I was looking because I know her, see. I took one look and I thought to meself, ‘Sammy, you know that lady.’ ”

Poirot shifted in his chair. He looked at me, then back at Kidd. “If you know her, Mr. Kidd, please tell us who she is.”

“I can’t, sir. That’s what I was trying to get straight in my head when she ran away. I don’t know how I know her, or her name, or nothing like that. It’s not from making boilers I know her, I can say that much. She looked refined. A proper lady. I don’t know anybody like that, but I do know her. That face—it’s not a face I saw last night for the first time. No, sir.” Samuel Kidd shook his head. “It’s a puzzle all right. I might have asked her, if she’d not run away.”

I wondered, out of all the people who ever ran away, how many did so for that very reason: because they would rather not be asked, whatever the question might be.

SHORTLY AFTER I HAD sent Samuel Kidd packing with orders to search his memory for the name of this mysterious woman and details of where and when he might have made her acquaintance, Constable Stanley Beer delivered Henry Negus to Pleasant’s.

Mr. Negus was considerably more pleasing to the eye than Samuel Kidd: a handsome man of around fifty with iron-gray hair and a wise face. He was smartly dressed and soft spoken. I liked him instantly. His grief at the loss of his brother was palpable, though he was a model of self-control throughout our conversation.

“Please accept my condolences, Mr. Negus,” said Poirot. “I am so sorry. It is a terrible thing to lose one so close as a brother.”