world; family physician, spiritual adviser, and all that sort of thing, from time immemorial. When Von Blon, senior, died we embraced the son as a matter of course. And young Arthur's a shrewd lad, too. Knows his pharmacopœia. Trained by the old man, and topped off his medical education in Germany."
Vance nodded negligently.
"While we're waiting for Doctor Von Blon, suppose we have a chat with Miss Sibella and Mr. Rex. Your brother first, let us say."
Greene looked to Markham for confirmation; then rang for Sproot.
Rex Greene came immediately upon being summoned.
"Well, what do you want now?" he asked, scanning our faces with nervous intensity. His voice was peevish, almost whining, and there were certain overtones in it which recalled the fretful complaining voice of Mrs. Greene.
"We merely want to question you about last night," answered Vance soothingly. "We thought it possible you could help us."
"What help can I give you?" Rex asked sullenly, slumping into a chair. He gave his brother a sneering look. "Chester's the only one round here who seems to have been awake."
Rex Greene was a short, sallow youth with narrow, stooping shoulders and an abnormally large head set on a neck which appeared almost emaciated. A shock of straight hair hung down over his bulging forehead, and he had a habit of tossing it back with a jerky movement of the head. His small, shifty eyes, shielded by enormous tortoise-rimmed glasses,
