Nightmare‪!‬

Nightmare! A Tale of Waking Terror is a science fiction lost world novel by Francis Stevens (pseudonym for Gertrude B. Bennett), "The woman who invented dark fantasy".

Nightmare! is set in a surreal Lost World embedded in a Pacific Island with a storyline that sometimes prefigures the Television series Lost.

When a tourist from New York sails on the ill-fated liner Lusitania, he wakens from a night's sleep to find himself struggling in the seas off an uncharted island. There, he encounters man-eating plants, spiders as big as a dining-room table, bears as large as elephants, and bats of similar proportions.

He also finds himself caught in a rivalry between two dangerous groups competing to extract a rare substance found only on the island which turns lead into gold. Then he meets the strong-minded woman who opposes both groups--and joins her cause.

But, the horrors of nature and the evil plans of greedy men are only the least of the dangers they must overcome, if they are to escape their nightmare!

Nightmare! first appeared in the April 14th issue of All-Story Weekly in 1917.

Gertrude Barrows Bennett (1883–1948) was the first major female writer of fantasy and science fiction in the United States, publishing her stories under the pseudonym Francis Stevens. Bennett wrote a number of highly acclaimed fantasies between 1917 and 1923 and has been called "the woman who invented dark fantasy".

Her most famous books include Claimed! (which Augustus T. Swift, in a letter to The Argosy called "One of the strangest and most compelling science fantasy novels you will ever read") and the lost world novel The Citadel of Fear.

Bennett has been credited as having "the best claim at creating the new genre of dark fantasy". It has been said that Bennett's writings influenced both H. P. Lovecraft and A. Merritt, both of whom "emulated Bennett's earlier style and themes".