theory is that she didn't count on our having a doctor handy to save Ada's life, and that, having failed to put Ada out of the way, she figured the game was up, and took the strychnine."
"That's it!" O'Brien struck the table with his fist. "And it makes sense. Furthermore, it means we've cleared up the case—see?"
"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
