MacKenzie Scott is releasing her third novel, "Last Days in Two Nations (A History in Eighteen Minds)," chapter by chapter on Substack through Aug. 31, opting for an open online platform rather than a traditional publisher or major bookseller. Scott, who studied under Toni Morrison at Princeton University, posted the title, epigraph, personae and contents on Saturday, followed by the prologue on Sunday and the first chapter, "Monday," on Monday. The 317-page book, excluding the epilogue, appears to center on a fictional religious community called the Church of the Long Tomorrow. The rollout marks Scott's first novel since 2013 and comes after years in which she has given more than $26 billion to charity while remaining one of the world's wealthiest women. Scott received roughly a 4% stake in Amazon in her 2019 divorce from Jeff Bezos after helping oversee early operations, business plans and contracts at the company in its early years. Although she has sold or donated about 58 million shares worth around $12.6 billion, reducing her original stake by about 42%, the Amazon shares she still owns have continued to appreciate. Amazon stock has risen nearly 69% over the past five years, helping sustain a net worth estimated at more than $38 billion even after her donations. Scott has long credited Morrison with shaping her writing career. Morrison supervised Scott's Princeton thesis, helped set her on the path to publishing her 2005 debut novel, "The Testing of Luther Albright," and later praised her as one of the best students she taught. "The Testing of Luther Albright" won an American Book Award in 2006.