The War of the Ring takes up the story of The Lord of the Rings with the Battle of Helm's Deep and the drowning of Isengard by the Ents, continues with the journey of Frodo, Sam and Gollum to the Pass of Cirith Ungol, describes the war in Gondor, and ends with the parley between Gandalf and the ambassador of the Dark Lord before the Black Gate of Mordor.
The book is illustrated with plans and drawings of the changing conceptions of Orthanc, Dunharrow, Minas Tirith and the tunnels of Shelob's Lair.