The Door of the Unreal is a horror novel by the British author Gerald Biss.

An early werewolf novel, praised by H.P Lovecraft, calling this novel one of the children of Dracula.

Two strange disappearances occur on a road in Sussex. The second involved a member of the aristocracy and a famous actress, so a large, but fruitless investigation is held by Scotland Yard.

An American, visiting an old friend, who is of the local gentry, suspects something horrible and begins to investigate to verify his fears.

”Werewolves, mysterious disapperances, and supernatural orgies make up this thrilling mystery story. The old belief in lycantrophy is made disturbingly credible, and the possibility that werevolves really exist seems far from remote.

A brilliant conceived experiment in the uncanny, which will keep the reader awake o’nights.”

Originally published in 1919, The Door of the Unreal is one of the first true werewolf classics, and helped to pave the way for the 'golden age' of the genre, which flourished in the two decades following the publication of Gerald Biss's novel.

At the time he wrote the novel Biss was largely covering uncharted territory: most of the now-familiar conventions of the werewolf tale had yet to be set in stone, and the author was not working to the type of narrow pattern which constrained many writers of vampire tales in the years following the publication of Dracula.

Edwin Gerald Jones Biss (1876–1922) was an English motoring journalist and crime writer. His stories were often serialised in journals and newspapers.

In 1903 his crime fiction was regularly appearing in newspapers in various parts of the country with serialised stories such as The Imposter; Bob Pharazin’s Madness; The White Rose; Who Killed Montagu Jerningham and later The Shadow of the Scaffold. The Dupe was published in 1907 and in 1908 The Fated Five — The Tale of a Great Tontine. This was followed by Branded, a story that in 1921 was made into a movie starring Josephine Earle. The House of Terror was published in 1909 and the Undying Dread serialised in 1911. The Door of the Unreal, published in 1920, was a werewolf story and a change of genre for Biss.