He noticed the ugly expression that came to the corners of the physician’s mouth. Burke shuddered instinctively.

“Come!”

THEY went back into the penthouse. Hassan arrived with two small glasses, containing a browning liqueur, that shone with specks of glistening gold. Burke took one glass, the doctor the other.

When Palermo raised the glass to his lips. Burke did likewise. The drink was new to him. It had a potency that he had never before experienced.

“Regarding Chatham,” said Doctor Palermo suddenly. “I regret very much that I did not have time to study his case. Had I done so, I would have possibly prevented a murder. I expected him to return at a later date.”

“Did you notice anything peculiar about his actions?” ventured Burke.

“In what way?”

“Did he — did he seem like himself? Or did he, perhaps, seem to have assumed a different personality?”

Doctor Palermo’s eyes narrowed, and Burke could almost feel their scrutiny. He regretted his question.

Perhaps it had been too leading.