It was a day or two later before Lawrence saw Prout again. In the meantime he had not been idle. In some vague way or another he felt sure he was on the track of the Corner House mystery. A dozen theories were formed and abandoned. If Prout had only possessed Lawrence\'s imagination!

"But is there anything in the letters?" the latter asked after Prout had given him a precis of their contents. "Something we can go by?"

"I\'m afraid not, sir," Prout admitted. "The only thing I have established so far is that my prisoner is the brother of the murdered man. Oddly enough, he has no idea that the writer of those letters is dead. And as he declines to disclose his own name, we cannot discover the identity of his murdered brother."

Lawrence read over the letters carefully, there was less here than he expected. They were all full of vague schemes of making money by various shady ways, and all bewailed the fact that the writer could not obtain the necessary capital to start. Really the letters were hardly worth reading.

But patience is generally rewarded. Here was a hiatus after a series of regular dates. The writer had been drinking heavily, somebody had got hold of him, and was detaining him somewhere against his will. He was not allowed to say where he was. His last letter of the series hinted at a possibility of large sums of money.

"I\'m afraid it\'s no good, sir," said Prout when Lawrence had finished.

"I don\'t quite agree with you," Lawrence said. "The man was detained again his will. Where was he detained? In the Corner House? Because his gaoler was afraid of his discretion. Now go a step further and ask who detained him yonder. You can answer that question for yourself."

"Countess Lalage," Prout muttered. "But why?"

"Ah, that is the point. Get to that, and the problem is solved. Now listen to me, Prout. The rascal who wrote those letters and the rascal who received them were brothers. They were fond of each other, which you will admit is possible. I see that for some reason of your own you have concealed the fact from the prisoner that his brother is no more. If you tell him the truth he will probably make some startling admission."

Prout nodded admiringly. Lawrence took a photograph from his pocket.

"Tell him the news abruptly," he said. "And when the man has digested that, show him the photograph. It is a recent one of Countess Lalage. I want to know if he recognises her."

Prout departed on his errand. It was easy enough for him to obtain a private interview with the prisoner, who received him with polite mockery. His instinct told him that Prout wished to learn something.

"You are welcome;" he said; "it is so dull here that even the conversation of a mere detective is pleasing."

"The detective was sharp enough to get you here," Prout said.

"Ah, well, even the great Napoleon made a mistake or two."

"Which you are likely to do yourself," said Prout, "if you try to be too smart. I want you to answer me a few questions, which don\'t affect your case at all. Give me the desired information, and I\'ll make matters as easy as I can for you on your trial. I can\'t get you off, but I can lighten the case."

The other man nodded. Prout was talking sense now.

"Go on, mon brave," he said. "I will do what I can for you--and myself."

"It\'s about those letters I found in your possession," Prout said, "the letters to you from your brother. I know they are from your brother, because I have seen him, and also his handwriting. You need not be afraid of him, because............