His eyes couldn't have been shut when the revolver was levelled at him, for he was standing, facing the intruder. It's inexplicable—mad!"
He beat a nervous tattoo on the table, his brows contracted.
"And there's another thing, Markham, that's incomprehensible about Rex's death. His door into the hall was open; but nobody up-stairs heard the shot—nobody up-stairs. And yet Sproot—who was down-stairs, in the butler's pantry behind the dining-room—heard it distinctly."
"It probably just happened that way," Markham argued, almost automatically. "Sound acts fantastically sometimes."
Vance shook his head.
"Nothing has 'just happened' in this case. There's a terrible logic about everything—a carefully planned reason behind each detail. Nothing has been left to chance. Still, this very systematization of the crime will eventually prove the murderer's downfall. When we can find a key to any one of the anterooms, we'll know our way into the main chamber of horrors."
At that moment Markham was summoned to the telephone. When he returned his expression was puzzled and uneasy.
"It was Swacker. Von Blon is at my office now—he has something to tell me."
"Ah! Very interestin'," commented Vance.
We drove to the District Attorney's office, and Von Blon was shown in at once.
"I may be stirring up a mare's nest," he began apologetically, after he had seated himself on the edge of a chair. "But I felt I ought to inform you
