Mountain of Black Glass is a science fiction novel by American writer Tad Williams, the third book in his Otherland series. It was first published in 1999 with a paperback edition in 2000.Green, Roland. "River of Blue Fire." Booklist, vol. 94, no. 18, 15 May 1998, p. 1566. Gale Academic OneFile, Accessed 19 February 2026.
Continuing from River of Blue Fire, it brings the characters together at the battle of Troy and finally to the heart of the Grail Brotherhood.
References
Forecasts: Fiction. Publishers Weekly. 1999;246(35):58. Accessed May 17, 2025. https://search.ebscohost.com/login.aspx?direct=true&db=lkh&AN=2231403&lang=ru&site=eds-live&scope=site Cassada J, Bryant E, Williams W, et al. Book reviews: Fiction. Library Journal. 1999;124(15):116. Accessed May 17, 2025. https://search.ebscohost.com/login.aspx?direct=true&db=lkh&AN=2291057&lang=ru&site=eds-live&scope=site