“You’re so comforting, Mr. Vance,” she said. “I’m sure you’re not a moralist; and you haven’t once condoled with me over my bereavements. Thank Heaven, we Greenes have no relatives to swoop down on us and bathe us in tears. I’m sure I’d commit suicide if we had.”
Vance and I called twice more within the week, and were received cordially. Sibella’s high spirits were always the same. If she felt the horror that had descended so suddenly and unexpectedly upon her home, she managed to hide it well. Only in her eagerness to talk freely and in her exaggerated efforts to avoid all sign of mourning did I sense any effects on her of the terrible experience she had been through.
Vance on none of his visits referred directly to the crimes; and I became deeply puzzled by his attitude. He was trying to learn something—of that I was positive. But I failed to see what possible progress he could make by the casual methods he was pursuing. Had I not known him better I might have suspected him of being personally interested in Sibella; but such a notion I dismissed simultaneously with its formulation. I noticed, however, that after each call he became unaccountably pensive; and one evening, after we had had tea with Sibella, he sat for an hour before the fire in his living-room without turning a page of the volume of da Vinci’s “Trattato della Pittura” which lay open before him.
On one of his visits to the Greene mansion he had met and talked with Rex. At first the youth had been surly and resentful of our presence; but before we went away he and Vance were discussing such subjects as Einstein’s general-relativity theory, the Moulton-Chamberlin planetesimal hypothesis, and Poincaré’s science of numbers, on a plane quite beyond the grasp of a mere layman like myself. Rex had warmed up to the discussion in an almost friendly manner, and at parting had even offered his hand for Vance to shake.
On another occasion Vance had asked Sibella to be permitted to pay his respects to Mrs. Greene. His apologies to her—which he gave a semiofficial flavor—for all the annoyance caused by the police immediately ingratiated him in the old lady’s good graces. He was most solicitous about her health, and asked her numerous questions regarding her paralysis—the nature of her spinal pains and the symptoms of her restlessness. His air of sympathetic concern drew from her an elaborate and detailed jeremiad.
Twice Vance talked to Ada, who was now up and about, but with her arm still in a sling. For some reason, however, the girl appeared almost farouche when approached by him. One day when we were at the house Von Blon called, and Vance seemed to go out of his way to hold him in conversation.
As I have said, I could not fathom his motive in all this apparently desultory social give-and-take. He never broached the subject of the tragedies except in the most indirect way; he appeared, rather, to avoid the topic deliberately. But I did notice that, however casual his manner, he was closely studying everyone in the house. No nuance of tone, no subtlety of reaction, escaped him. He was, I knew, storing away impressions, analyzing minute phases of conduct, and probing delicately into the psychological mainsprings of each person he talked to.
We had called perhaps four or five times at the Greene mansion when an episode occurred which must be recounted here in order to clarify a later development of the case. I thought little of it at the time, but, though seemingly trivial, it was to prove of the most sinister significance before many days had passed. In fact, had it not been for this episode there is no telling to what awful lengths the gruesome tragedy of the Greenes might have gone; for Vance—in one of those strange mental flashes of his which always seemed wholly intuitive but were, in reality, the result of long, subtle reasoning—remembered the incident at a crucial moment, and related it swiftly to other incidents which in themselves appeared trifling, but which, when coordinated, took on a tremendous and terrible importance.
During the second week following Chester Greene’s death the weather moderated markedly. We had several beautiful clear days, crisp, sunshiny, and invigorating. The snow had almost entirely disappeared, and the ground was firm, without any of the slush that usually follows a winter thaw. On Thursday Vance and I called at the Greene mansion earlier than on any previous visit, and we saw Doctor Von Blon’s car parked before the gate.
“Ah!” Vance observed. “I do hope the family Paracelsus is not departing immediately. The man lures me; and his exact relationship to the Greene family irks my curiosity.”
Von Blon, as a matter of fact, was preparing to go as we entered the hallway. Sibella and Ada, bundled in their furs, stood just behind him; and it was evident that they were accompanying him.
“It was such a pleasant day,” explained Von Blon, somewhat disconcertedly, “I thought I’d take the girls for a drive.”
“And you and Mr. Van Dine must come with us,” chimed in Sibella, smiling hospitably at Vance. “If the doctor’s temperamental driving affects your heart action, I promise to take the wheel myself. I’m really an expert chauffeur.”
I surprised a look of displeasure on Von Blon’s face; but Vance accepted the invitation without demur; and in a few moments we were riding across town, comfortably installed in the doctor’s big Daimler, with Sibella in front, next to the driver’s seat, and Ada between Vance and me in the tonneau.
We went north on Fifth Avenue, entered Central Park, and, emerging at the 72nd Street entrance, headed for Riverside Drive. The Hudson
