As soon as the plain-clothes men had gone, Blake spoke to Luke Froy. Curiously, the secret-service man’s words were in the Chinese native dialect that Luke Froy used. A puzzled look appeared upon his face. Then he began to plead in his native tongue. He was looking squarely into the eyes of his inquisitor, and in those eyes Luke Froy saw understanding. He made a short statement and Blake stopped him.
“What!” the secret-service man exclaimed in English. “Another letter?”
Luke Froy nodded.
“Cardona!” called Blake.
A REPLY came from the other room. Cardona’s face appeared. He saw the secret-service man covering the Chinaman with a gun.
“Did you get a Double Z letter today?”
“Yes,” admitted Cardona. This was the statement he had held back at headquarters. “Here it is. But it doesn’t mean anything now. We’ve got Double Z.”
Blake seized the paper. He read the message aloud:
“Barnaby Hotchkiss. Blaine Glover. Tonight. They are to die by my own hand.”
“See?” said Cardona. “Signed by Double Z — and we’ve got him! Just found out his name, Zachary Shellmann. There’s the Z for you—”