"How did you discover it?"
He heard Avery, who had been standing, come forward and seat himself on the arm of the chair across the table from him; the blind man turned to face this place directly.
"It was plain from the first there was something wrong with the man," Avery replied; "but I had, of course, no way of placing him until he gave himself away at polo the other day."
"At polo? Then you knew about it the other day?"
"Oh, no," Avery denied. "I saw that he was pretending not to know a game which he did know; when he put over one particular stroke I was sure he knew the game very well. The number of men in this country who've played polo at all isn't very large and those who can play great polo are very few. So I sent for the polo annuals for a few years back; the ones I wanted came to the club to-day. His picture is in the group of the Spring Meadows Club; he played 'back' for them five years ago. His name was under the picture, of course."
"You didn't tell me, however, that he could play polo when you first found it out."
"No; I wanted to be sure of him before I spoke; besides, Harriet had seen it as well as I; I supposed she had told you."
"I understand. I am glad to know how it was. One less certain of your fidelity than I am might have put another construction on your silence; one less certain, Avery, might have thought that, already knowing Eaton's identity, you preferred instead of telling it to me to have me discover it for myself and so, for that reason, you trapped him into a polo game in Harriet's presence. I, myself, do not think that. The other possibility which might occur to one not certain of your fidelity we will not now discuss."
For a moment Santoine paused; the man across from him did not speak, but—Santoine's intuition told him—drew himself suddenly together against some shock; the blind man felt that Avery was watching him now with tense questioning.
"Of course," said Santoine, "knowing who Eaton is, gives us no aid in determining who the men were that fought with him in my study last night?"