Sproot had no visible friends, and his acquaintances were limited to an English valet in Park Avenue and the tradespeople of the neighborhood. He was solitary by nature, and what few recreations he permitted himself were indulged in unaccompanied. Mrs. Mannheim had rarely left the premises of the Greene house since she had taken up her duties there at the time of her husband's death, and apparently knew no one in New York outside of the household.
These reports dashed whatever hopes Sergeant Heath may have harbored of finding a solution to the Greene mystery by way of a possible accomplice in the house itself.
"I guess we'll have to give up the idea of an inside job," he lamented one morning in Markham's office a few days after the shooting of Chester Greene.
Vance, who was present, eyed him lazily.
"I shouldn't say that, don't y' know, Sergeant. On the contr'ry, it was indubitably an inside job, though not just the variety you have in mind."
"You mean you think some member of the family did it?"
"Well—perhaps: something rather along that line." Vance drew on his cigarette thoughtfully. "But that's not exactly what I meant. It's a situation, a set of conditions—an atmosphere, let us say—that's guilty. A subtle and deadly poison is responsible for the crimes. And that poison is generated in the Greene mansion."
"A swell time I'd have trying to arrest an atmosphere—or a poison either, for the matter of that," snorted Heath.
