In that sentence was concealed, doubtless, the secret of why the crime had been committed, and Nick Carter felt as certain as he had ever felt assured of anything in his life, that the dead girl on the couch, if she could have come to life at that moment, would have been utterly ignorant of what those reasons were.
In other words Nick Carter read the scene in this manner:
This crime was committed to conceal another crime, and the murderer, knowing that his lesser crime would presently be discovered, determined to fix it upon this innocent girl, the daughter of the house.
Therein existed the nucleus of the whole affair as the detective saw it.
It was plain, of course, that the man who could have induced Edythe Lynne to go with him to her out-of-town home in the dead of night must have been a near relative, or a person who was entirely in the confidence of the family—otherwise she would not have consented to accompany him.
And even then there must have been a powerful motive beyond any that could appear on the surface.
Was the man who had done this thing young or old, or middle aged? There was no present means of ascertaining that, but that he must be one who stood upon terms of at least cordial familiarity with J. Cephas Lynne and his daughter was beyond doubt.
The detective made one further hasty survey of the room, throwing the beam of his flash light again upon every detail that he had discovered; and then he left the room, leaving every detail as he had found it, save only the letter which he carried away with him in his pocket.
It was snowing hard when he got outside, and he nodded, as if to say:
“The murderer foresaw this additional fall of snow, and hence took no trouble to cover his tracks.�