"That answers only one of my points. In my consideration of this aspect of the case, two possible solutions occurred to me. It is impossible for any of the guests to have committed the crime, because they were all downstairs at the time, but it is just possible one of them may have instigated it."
"It is incredible to me that a guest staying in a gentleman's house could plot such a crime," said Captain Stanhill.
"Nothing is incredible in crime," replied Merrington. "I've no illusions about human nature. It is capable of much worse things than that. Strange things can happen in a big country-house like this, filled with a large party of young people of both sexes—flirtations, intrigues, and worse still."
"But not murder, as a general rule," commented Captain Stanhill, with a trace of sarcasm in his mild tones.
"You cannot lay down general rules about murder. An unbalanced human being, under the influence of hatred, jealousy, or revenge, is no more amenable to the rules of society than a tiger. But I do not think that this crime was instigated by one of the guests, because in that case it would probably have been arranged to be committed later in the evening, when the members of the house-party were at the house of the Weynes, and the moat-house was occupied only by the servants. Still, I do not intend to lose sight of the hypothesis. Another possibility is that one of the servants was in league with the murderer. A third possibility is that Mrs. Heredith may have brought in the murderer herself."
"What do you mean?"
"She may have had a lover, and the lover may have murdered her."
"Oh, impossible!" Captain Stanhill repelled the idea with an instinctive gesture of disgust. "It is too monstrous to suppose that a happily married young wife would be carrying on an intrigue three months after her marriage."
"More monstrous things happen every day—human nature being what it is," retorted Merrington coolly. "You must remember that we know practically nothing about her. The people who knew her in London left the house before they could be questioned; Miss Heredith and her brother have no knowledge of her past; and her husband is too ill to tell us anything. Her marriage was apparently a hasty love match—a love match so far as young Heredith was concerned. So far, we have only two slender facts to guide us in our estimate of her, which are contained in the two letters in which young Heredith announced his marriage to his people. According to those statements, she was an orphan who was earning her living as a war clerk in the Government department in which young Heredith held his appointment. That does not carry us very far. During her brief life at the moat-house she seems to have been reticent about her earlier life. Miss Heredith is not the type of woman to have questioned her, and, apparently, she vouchsafed no information. An examination of her boxes and her writing-table has brought to light nothing in the way of writing or correspondence to help us. Such a girl—a bachelor girl in London in war-time—may have had passages in her past life of which her husband knew nothing—passages which may have an important bearing on her murder. Not until we have a thorough knowledge of her antecedents and her past life can we hope to pierce the hidden motives which have led to this murder. It is there, in my opinion, that we must seek for the clue to this strange murder, and it is to that effort I shall devote my energies as soon as I return to London. Until those facts are brought to light we are merely groping in the dark."