It is frequently said that the whole art of a mystery story or detective story of the kind Mrs. Green writes is to direct suspicion at every person except the right one, until the end! This is clever and partly true, but it takes no account of the vast amount of construction which must go forward before a sentence of the story can be put on paper; it ignores the fact that the criminal, to be convincing, must have figured in the story from the start, for otherwise he will appear as a desperate invention to help the author out of an otherwise insoluble situation. Looking at _Dark Hollow_ in retrospect it is quite easy to see why certain things had to be--so. Judge Ostrander had to be the murderer because he was the person least likely to kill his dearest friend. Oliver had to be under suspicion to make Judge Ostrander’s confession plausible. The Judge had to be the murderer, furthermore, that Reuther Scoville might not be an unfit person to become the wife of Oliver. Oliver had to be cleared that he might be fit to mate with Reuther! Yes, yes; but all this wisdom after the event gets nowhere. It does not penetrate to the heart of the action and throws no light on the author’s cunning. Do you suppose for a moment that she made her story out of such nice little expediencies as these? You can’t build a story that way. It won’t hold together for a moment. No! The real starting point in _Dark Hollow_ was the conception on the part of Mrs. Green of a man who should, in a moment’s fit of passion, slay his closest friend and who should thereafter, for twelve years, inflict on himself a peculiar punishment, imprisoning himself in a convict’s cell _in his own home_! All the rest--the painting of a black band across the eyes of his son’s portrait that they might not look on his father, murderer and coward; the sending of that son away from home for all time; the building of a double fence to guard against intrusion by so much as an eye at a knothole--all these followed. Then on this solid foundation of a single life, a single idea, a single stricken conscience arose, course by course, the complicated and wonderful (but solid and sound) structure of the book.