It was next necessary to reconstruct the crime. A period of twenty minutes or half an hour at a given place was under consideration. Where was this place and where did it stand with respect to every other place in the story--Judge Ostrander’s house, the Claymore Inn, the ruin of Spencer’s Folly? A map had to be made. It is an illustration in the book. But much more than a map was necessary. The exact whereabouts of every one of half a dozen persons for the whole twenty minutes or half hour had to be settled. Etheridge, Scoville, Mrs. Scoville, Oliver and Judge Ostrander were all in or near Dark Hollow. Just where was each at every moment? Just what was each doing? Just what could, and did, each say and do and hear and see? The author must know _all_ these things in order to spare the reader what is irrelevant. She must have every inch of the ground at her fingertips and every instant clear. You don’t believe this? Try writing a story like _Dark Hollow_, improvising as you go along, or working from a mere outline, and see what happens to you! The only improvisation in such work as Mrs. Green’s is in respect of what might be called chapter climaxes--the brief thrills, one or more to a chapter, which arise, administer their shock to the reader’s nerves, and are cleared up some pages later. Many of these are planned in advance, a few suggest themselves as the writer goes along, others are real inspirations which have suggested themselves during the writing and are substituted for planned but less effective climaxes. Such is the incident cited above where two trains, one bound south and the other bound for Canada, meet and pass at the little mountain station.