Complex sentence: He continues to labor on a second novel, but the more he tries to finish it the less able he finds himself to invent a satisfactory ending--the book runs to over two and a half thousand pages and is still far from finished.
Split into simpler sentences: He continues to labor on a second novel, but the more he tries to finish it the less able he finds himself to invent a satisfactory ending. The book runs to over two and a half thousand pages and is still far from finished.