The Shunned House -- Managing Long Documents, Page size and margins, step 2

Since "The Shunned House" is over 60k characters long, one usually wonders if there is a way to subdivide this document in more manageable pieces. It would be neat to follow document's structure and create a separate file for every chapter, and a central document file to assemble all chapters in a single book.
It turns out that TeX -- and ConTeXt has such a mechanism. The \input <texfile> command tells TeX to search and load a TeX subdocument into the main document. With this feature, we can thus subdivide "The Shunned House" in five chapter, each beginning with \chapter{} and each ending with \stopcolumns.