“Yes, it unquestionably makes sense.” It was Vance’s quiet, drawling voice that answered. “But forgive me if I suggest that it fits the facts much too tidily. It’s a perfect theory, don’t y’ know; it leaps to the brain, almost as though some one had planned it for our benefit. I rather fancy that we’re intended to adopt that very logical and sensible point of view. But really now, Inspector, Mrs. Greene was not the suicidal type, however murderous she may have been.”
While Vance had been speaking, Heath had left the room. A few minutes later he returned and interrupted O’Brien in a long, ill-natured defense of his suicide theory.
“We haven’t got to argue any more along that line,” he announced. “I’ve just had Doc Doremus on the phone. He’s finished the autopsy; and he says that the old lady’s leg muscles had wasted away—gone plumb flabby—and that there wasn’t a chance in the world of her moving her legs, let alone walking on ’em.”
“Good God!” Moran was the first to recover from the amazement this news had caused us. “Who was it, then, that Ada saw in the hall?”
“That’s just it!” Vance spoke hurriedly, trying to stem his rising sense of excitation. “If only we knew! That’s the answer to the whole problem. It may not have been the murderer; but the person who sat in that library night after night and read strange books by candlelight is the key to everything. . . .”
“But Ada was so positive in her identification,” objected Markham, in a bewildered tone.
“She’s hardly to be blamed in the circumstances,” Vance returned. “The child had been through a frightful experience and was scarcely normal. And it is not at all unlikely that she, too, suspected her mother. If she did, what would have been more natural than for her to imagine that this shadowy figure she saw in the hall long after midnight was the actual object of her dread? It is not unusual for a person under the stress of fright to distort an object by the projection of a dominating mental image.”
“You mean,” said Heath, “that she saw somebody else, and imagined it was her mother because she was thinking so hard of the old woman?”
“It’s by no means improbable.”
“Still, there was that detail of the Oriental shawl,” objected Markham. “Ada might easily have mistaken the person’s features, but her insistence on having seen that particular shawl was fairly definite.”