Lexy rose, too. His tone, his manner, exasperated her almost beyond endurance. She felt an ardent desire to contradict everything he said. What is more, she was in no humor to hear mystery stories made light of. She had had enough of that—first Mrs. Enderby pretending there was no mystery, and then Mr. Houseman going off and pretending it was solved, so that she was left alone to do the best she could. Wasn’t she in a mystery story at this very minute, and without a single promising clew to guide her? “There are plenty of mysteries that aren’t fiction,” she observed curtly. “But they are never solved,” said Dr. Quelton. “Never solved?” said Lexy. “But lots of them are! You can read in the newspapers all the time about crimes that—” “The mystery of a crime is never solved,” the doctor blandly proceeded. “Never! Let us say, for example, that a murder is committed. The police investigate, they arrest some one. There is a trial, the jury finds that the suspect is guilty, the judge sentences him, and he is executed. Public opinion is satisfied; but as a matter of fact, nothing whatever has been solved. It is all guesswork. Not one living soul, not one member of the jury, not the judge, not the executioner, really _knows_ that the accused man was guilty. They think so—that is all. What you call a ‘solution’ is merely a guess, based upon probabilities.” Lexy considered this with an earnest frown. “Well,” she said at last, “quite often criminals confess.” “In the days of witchcraft trials,” said he, “it was not uncommon for women to come forward voluntarily and confess to being witches. In the course of my own practice I have known people to confess things they could not possibly have done. No!” He shook his head and smiled faintly. “An acquaintance with the psychology of the diseased mind makes one very skeptical about confessions, Miss Moran.” This idea, too, Lexy took into her mind and considered for a few minutes. “Even an eyewitness,” Dr. Quelton went on, “is entirely unreliable. Any lawyer can tell you how completely the senses deceive one. Three persons can see the same occurrence, and each one of the three will swear to a quite different impression. Each one may be entirely honest, entirely convinced that he saw or heard what never took place.” “Do you mean that you think it’s never possible to find out who’s guilty?” “Never,” he replied agreeably. “It can never be anything but a guess, as I said, based upon probabilities. Human senses, human judgment, human reason, are all pitifully liable to error.” Lexy was silent for a time, thinking over this. “Maybe you’re right,” she said slowly, “about the senses, and judgment, and reason. Perhaps their evidence isn’t always to be trusted; but there’s something else.” “Something else?” he repeated. “Something else? And what may that be?”