“I am indebted both to Dorcas and to you, madame,” said Poirot. “When I arrived here only—what is it?—half an hour ago, I did not see clearly. I saw only confusion and puzzles. Now, I begin to put things together . . . It is very important that I should think without interruption.”

“Oh.” Louisa looked disappointed. “Well, if you need to hurry off—”

“Oh, no, no, you misunderstand me. Pardon, madame. The fault is mine: I did not make myself clear. Of course we must finish the tour of the art. There is much still to explore! After that, I shall depart and do my thinking.”

“Are you sure?” Louisa regarded him with something akin to alarm. “Well, all right, then, if it’s not too much of a bore.” She recommenced her enthusiastic commentary on her husband’s pictures as Poirot and Louisa moved from room to room.

In one of the guest bedrooms, the last upstairs room that they came to, there was a white jug and bowl set with a red, green and white crest on it. There was also a wooden table, and a chair; Poirot recognized both from Nancy Ducane’s painting of Louisa. He said, “Pardon, madame, but where is the blue jug and bowl from the portrait?”

“The blue jug and bowl,” Louisa repeated, seemingly confused.

“I think you posed for Nancy Ducane’s painting in this room, n’est-ce pas?”

“Yes, I did. And . . . wait a minute! This jug and bowl set is the one from the other guest bedroom!”

“And yet it is not there. It is here.”

“So it is. But . . . then where is the blue jug and bowl?”

“I do not know, madame.”

“Well, it must be in a different bedroom. Mine, perhaps. Dorcas must have swapped them around.” She set off at a brisk pace in search of the missing items.

Poirot followed. “There is no other jug and bowl set in any of the bedrooms,” he said.

After a thorough check, Louisa Wallace said through gritted teeth, “That useless girl! I’ll tell you what’s happened, Monsieur Poirot. Dorcas has broken it and she’s too scared to tell me. Let us go and ask her, shall we? She will deny it, of course, but it’s the only possible explanation. Jugs and bowls don’t disappear, and they don’t move from room to room on their own.”

“When did you last see the blue jug and bowl, madame?”

“I don’t know. I haven’t noticed them in a long while. I hardly ever go into the guest bedrooms.”

“Is it possible that Nancy Ducane removed the blue jug and bowl when she left here on Thursday night?”