"The Fall of Gondolin" is a posthumously published novel by J.R.R. Tolkien, edited by his son Christopher Tolkien. The book tells the story of the fall of the hidden elven city of Gondolin, a story that Tolkien began writing in 1916 and reworked several times throughout his life.

The book begins with a brief introduction by Christopher Tolkien, explaining the history of the writing of "The Fall of Gondolin" and the editorial decisions he made in compiling the final version of the story.

The story is set in the First Age of Middle-earth, and follows the character of Tuor, a man of the house of Hador, who is guided by the elven lord Ulmo on a quest to find the hidden city of Gondolin. When Tuor arrives at Gondolin, he is welcomed by the king Turgon, who allows him to live in the city and marries his daughter, Idril.

The story soon takes a dark turn when the evil Morgoth, the master of Sauron, sends his army of orcs and balrogs to attack Gondolin. Tuor, Idril, and their son Earendil are able to escape, but the city is destroyed, and many of its inhabitants are killed in the battle.

The book includes several previously unpublished illustrations by J.R.R. Tolkien, as well as maps and genealogical tables to help readers understand the complex relationships between the characters.

"The Fall of Gondolin" is a must-read for fans of J.R.R. Tolkien's work, particularly those interested in the early history of Middle-earth. It provides a glimpse into the evolution of Tolkien's writing and storytelling, and offers a new perspective on the epic battles and heroic characters that populate his fictional universe.

The prose is rich and evocative, immersing readers in the world of Middle-earth and the conflicts that shaped it. The characters are well-drawn and complex, with motivations and desires that drive the plot forward. The themes of sacrifice, loyalty, and the struggle between good and evil are explored with depth and nuance, making "The Fall of Gondolin" a satisfying and thought-provoking read.