A previously unpublished story by J.R.R. Tolkien is hitting bookshelves. The Story of Kullervo is set to shed more light on the world of Middle-earth.

On August 27, U.K. residents will be able to purchase a brand new book by J.R.R. Tolkien. U.S. fans will have to wait until October 27.

The unfinished manuscript was one of the Lord of the Rings author’s first attempts to write a fantasy story. Tolkien himself called it, “the germ of my attempt to write legends of my own.”

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Although The Story of Kullervo is based on the 19th century Finnish epic poem “Kalevala,” it ties into the Middle-earth lore we know and love from The Lord of the Rings and The Hobbit.

The story takes place during the First Age of the world, and Kullervo is an ancestor of one of the central figures in The Silmarillion, Túrin Turambar.

Here’s the official synopsis from Amazon:

Kullervo son of Kalervo is perhaps the darkest and most tragic of all J.R.R. Tolkien’s characters. ‘Hapless Kullervo’, as Tolkien called him, is a luckless orphan boy with supernatural powers and a tragic destiny.

Brought up in the homestead of the dark magician Untamo, who killed his father, kidnapped his mother, and who tries three times to kill him when still a boy, Kullervo is alone save for the love of his twin sister, Wanona, and guarded by the magical powers of the black dog, Musti. When Kullervo is sold into slavery he swears revenge on the magician, but he will learn that even at the point of vengeance there is no escape from the cruellest of fates.

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Further, Amazon writes, “In addition to it being a powerful story in its own right, The Story of Kullervo – published here for the first time with the author’s drafts, notes and lecture-essays on its source-work, “The Kalevala” – is a foundation stone in the structure of Tolkien’s invented world.”

The Story of Kullervo was first published in an academic journal of Tolkien Studies, but this will be its first major market release.