“Why should he do that, Ursula?”

She did not answer him at once, because here Carver interposed a question.

“How long have you known, Miss Ardfern, that Lander was the murderer of Jesse Trasmere?”

Tab expected her to say that she did not know it at all, and that the news had come in the nature of a shock. Instead:

“I knew he was the murderer the day that Tab told me about the will Mr. Trasmere had left.”

“But why?” asked Tab.

“Because,” said Ursula, “Mr. Trasmere could not read or write English!”

The full significance of the simple statement came more quickly to Carver than to Tab.

“I see. I’ve known the will was a fake all the time,” he said, “but I thought it was just a forgery, and that Lander had imitated the writing of the letters that used to come for him from the old man.”

“They never came from the old man, Mr. Lander wrote them himself,” said the girl. “I rather think he wrote them with the intention of establishing the authenticity of the signature when the will was discovered. He had guessed the old gentleman’s secret. Mr. Trasmere was very sensitive on the point. He used to complain that although he could write and read Chinese without any difficulty—in fact, I have learnt since that he was scholarly in that direction—he could not write two words of English. That is the principal explanation as to why he employed me for his secretary, and why he must have somebody upon whom he could place the utmost reliance, and on whom he had some sort of pull.”