“Do you suspect Oscar?” Lukens asked.
“Perhaps.”
“Willis?”
“Perhaps. I even suspected you, Doctor Lukens.”
The physician gasped in indignation.
“I watched you,” said the visitor. “You did not see me here. Your interest in the false code showed that you did not know it was spurious. I resolved to explain the matter to you and to ask your aid.”
“How can I aid you?”
“By living here as an executor of Marchand’s estate. Study the two men who lived with Marchand. Watch for new developments.”
Doctor Lukens nodded.
“In the meantime,” continued the stranger, “I shall investigate others who—”