When Gene Wolfe

Gene Wolfe

Gene Wolfe is an American science fiction and fantasy writer. He is noted for his dense, allusive prose as well as the strong influence of his Catholic faith, to which he converted after marrying into the religion. He is a prolific short story writer and a novelist, and has won many awards in the...

 finished the third volume of his The Book of the New Sun

The Book of the New Sun

The Book of the New Sun is a novel in four parts written by science fiction and fantasy author Gene Wolfe. It chronicles the journey and ascent to power of Severian, a disgraced journeyman torturer who rises to the position of Autarch, the one ruler of the free world...

heroic fantasy

Heroic fantasy

Heroic fantasy is a sub-genre of fantasy which chronicles the tales of heroes in imaginary lands. Unlike stories of sword and sorcery, heroic fantasy narratives tend to be intricate in plot, often involving many peoples, nations and lands. Grand battles and the fate of the world are common themes,...

 epic, fans of the series began clamoring almost immediately for the fourth and final book in the tetralogy

Tetralogy

A tetralogy is a compound work that is made up of four distinct works, just as a trilogy is made up of three works....

. As time passed and this concluding volume did not materialize, they began to root about for any information concerning the book, which did not even have a working title

Working title

A working title, sometimes called a production title, is the temporary name of a product or project used during its development, usually used in filmmaking, television production, novel, video game, or music album.-Purpose:...

. The first glimmer was the title, which was announced by the Locus

Locus (magazine)

Locus, subtitled "The Magazine Of The Science Fiction & Fantasy Field", is published monthly in Oakland, California. It reports on the science fiction and fantasy publishing field, including comprehensive listings of all new books published in the genre. It is considered the news organ and trade...

 magazine as The Castle of the Otter.

The Citadel of the Autarch was the actual name of the final work in the series. Author Gene Wolfe liked the inaccurate title, though, and used it as the name for a companion work of non-fiction essays and un-used materials from the series (including an article about how Otter got its title).

The Castle of the Otter (1982, ISBN 0-917488-10-5) is something of a collector's item. Originally published as a small press edition by Mark V. Ziesing

Mark V. Ziesing

Mark V. Ziesing is a small press publisher and bookseller. Active as a bookseller from 1972 to present, Ziesing was active in publishing from the mid-1980s into the late 1990s. The Ziesing publishing imprint specialized in science fiction, horror, and other forms of speculative fiction...

, it was also offered for sale through the Science Fiction Book Club

Book sales club

A book sales club is a subscription-based method of selling and purchasing books. It is more often called simply a book club, a term that is also used to describe a book discussion club, which can cause confusion.-How book sales clubs work:...

.

The material in Castle of the Otter was combined with his short story collection Gene Wolfe's Book of Days

Gene Wolfe's Book of Days

Gene Wolfe's Book of Days is a short story collection by American science fiction author Gene Wolfe published in 1981 by Doubleday.The stories within the collection are each paired with a holiday within the calendar year that is thematically linked to the content of the story...

to make the volume Castle of Days.