The old slippers had been the only kind which the murderer could wear, and he or she had put them on and had gone out again, after making the circuit of the house.

Why had this mysterious person tried to get into the house again, and for whom or what were they searching?
If Ling Chu was correct, obviously the murderer could not be Milburgh.

If he could believe the evidence of his senses, the man with the small feet had been he who had shrieked defiance in the darkness and had hurled the vitriol at his feet.

He put his views before his subordinate and found Whiteside willing to agree with him.
"But it does not follow," said Whiteside, "that the bare-footed person who was apparently in Mrs.Rider's house committed the murder.

Milburgh did that right enough, don't worry! There is less doubt that he committed the Daffodil Murder." Tarling swung round in his chair; he was sitting on the opposite side of the big table that the two men used in common.
"I think I know who committed the Daffodil Murder," he said steadily.
"I have been working things out, and I have a theory which you would probably describe as fantastic." "What is it ?" asked Whiteside, but the other shook his head.
He was not for the moment prepared to reveal his theory.
Whiteside leaned back in his chair and for a moment cogitated.
"The case from the very beginning is full of contradictions," he said.
"Thornton Lyne was a rich man--by-the-way, you're a rich man, now, Tarling, and I must treat you with respect." Tarling smiled.
"Go on," he said.
"He had queer tastes--a bad poet, as is evidenced by his one slim volume of verse.