The professor nodded and gave him a searching look.
“That is true. I see you, too, noticed that peculiar circumstance. I don’t quite understand why Pardee should have shut the windows.”
“The idiosyncrasies of suicides have never been satisfactorily explained,” returned Vance casually. Then, after a short pause, he asked: “What were you and Mr. Pardee talking about during the hour preceding his departure?”
“We talked very little. I was more or less engaged with a new paper of Millikan’s in the Physics Review on alkali doublets, and I tried to interest him in it; but his mind, as I’ve said, was noticeably preoccupied, and he amused himself at the chess-board for the best part of the hour.”
“Ah! Did he, now? That’s most interestin’.”
Vance glanced at the board. A number of pieces were still standing on the squares; and he rose quickly and crossed the room to the little table. After a moment he came back and reseated himself.
“Most curious,” he murmured, and very deliberately lighted a cigarette. “He was evidently pondering over the end of his game with Rubinstein just before he went down-stairs last night. The pieces are set up exactly as they were at the time he resigned the contest—with the inevitable black-bishop-mate only five moves off.”
Professor Dillard’s gaze moved to the chess table wonderingly.
“The black bishop,” he repeated in a low tone. “Could that have been what was preying on his mind last night? It seems unbelievable that so trivial a thing could affect him so disastrously.”
“Don’t forget, sir,” Vance reminded him, “that the black bishop was the symbol of his failure. It represented the wreckage of his hopes. Less potent factors have driven men to take their own lives.”