The novel The Adventures of Kathlyn was also a serial film, produced as thirteen episodes and starring Kathlyn Williams. MacGrath wrote both simultaneously, timing things so the novel would be in the bookstores when the serial was running. The serial was only the second serial made by an American company, and the first of the "cliffhanger" style that became popular over the next decade. It was popular enough to spawn a feature-length film a couple of years later with the same title and largely the same cast.Harold MacGrath was known for writing novels, short-stories, and even screenplays for the then-nascent movie industry. He wrote at least a novel a year, had short stories in the Saturday Evening Post and Ladies' Home Journal, and became one of the first well-known writers to work in film.!