“Yes,” replied Peret calmly. “Even without clues to work with, this would not have been very difficult. Of the several nations that have been trying to get possession of the Q-gas formula there are only one or two that would authorize their agents to go to such extremes as were employed last night to acquire it, and as virtually all of their agents are known to the Secret Service, our search would have been confined to a limited group of men and women. It would simply have been a matter of elimination.”
Deweese nodded his understanding, and the sleuth continued:
“Almost from the very first, however, for reasons which I will explain later, I was led to suspect a man who has since turned out to be a notorious international agent, known in diplomatic circles as Count Vincent di Dalfonzo. During his absence, I made a somewhat hurried search of his rooms after my departure from the scientist’s house, but could find nothing to incriminate him.
“One of my operatives, however, a former Secret Service agent, was able to identify him, if nothing more. According to this operative, Dalfonzo, who is one of the greatest scoundrels unhung, at the present time bears the secret credentials of a nation I will leave unnamed, but one which, I have reason to know, has made several unsuccessful attempts to buy the Q-gas formula from Berjet.”
Deweese was leaning forward in his chair, an eager listener. As Peret paused to relight his cigarette, he remarked:
“If Dalfonzo is such a notorious character, one would have thought that the Secret Service would have kept him under its eye.”
“One would have thought so, indeed,” agreed Peret, expelling a cloud of smoke from his lungs. “When last heard of several months ago, Dalfonzo was in Petrograd and he probably entered this country in disguise and has since kept himself well under cover.”
“Have you arrested him?”
“I have scarcely had time yet, Monsieur,” answered Peret. “I feel safe in saying, however, that he will be in the custody of the police within the next twenty-four hours.”
“Good! I will never feel safe while this scoundrel is at large, if indeed he really did have a hand in the murders of Berjet, Sprague and Adolphe, and the attack on me.”