Hallucination is a science fiction

Science fiction

Science fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...

 short story

Short story

A short story is a work of fiction that is usually written in prose, often in narrative format. This format tends to be more pointed than longer works of fiction, such as novellas and novels. Short story definitions based on length differ somewhat, even among professional writers, in part because...

 by Isaac Asimov

Isaac Asimov

Isaac Asimov was an American author and professor of biochemistry at Boston University, best known for his works of science fiction and for his popular science books. Asimov was one of the most prolific writers of all time, having written or edited more than 500 books and an estimated 90,000...

, and has been included in Gold

Gold (Asimov)

Gold: The Final Science Fiction Collection is a collection of Isaac Asimov's stories and essays. The stories, which comprise its first half, are short pieces which had remained uncollected at the time of Asimov's death. As such, they have been criticized by some as inept or below par—what the...

. Hallucination was published and copyrighted in 1995, three years after Asimov died in 1992. As such, it is unclear when the short story was written but its storyline is similar to that of his novel

Novel

A novel is a book of long narrative in literary prose. The genre has historical roots both in the fields of the medieval and early modern romance and in the tradition of the novella. The latter supplied the present generic term in the late 18th century....

 Nemesis

Nemesis (Asimov)

Nemesis is a science fiction novel by American writer Isaac Asimov. One of his later science fiction novels, it was published in 1989, only three years before his death...

.

Plot summary

Hallucination takes place at a time in the future although the exact date or era is not specific. The action takes place on Energy Planet, a rocky earth-like planet orbiting a neutron star

Neutron star

A neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star during a Type II, Type Ib or Type Ic supernova event. Such stars are composed almost entirely of neutrons, which are subatomic particles without electrical charge and with a slightly larger...

 in the Milky Way

Milky Way

The Milky Way is the galaxy that contains the Solar System. This name derives from its appearance as a dim un-resolved "milky" glowing band arching across the night sky...

. All characters are human (as are most of Asimov's characters) except the extraterrestrial insectoid

Insectoid

Insectoid denotes any creature or object that shares a similar body or traits with common earth insects and arachnids. The term is a combination of "insect" and "-oid" . Compare "humanoid"....

s. The story is divided into three parts.

Part One: The main character, Sam Chase, a fifteen-year-old, reluctantly arrives on Energy Planet. There he will serve a three-year tour of duty with an unnamed terrestrial military group while receiving training in gravitational engineering. The Central Computer (a successor of Asimov's Multivac

Multivac

Multivac is the name of a fictional supercomputer in many stories by Isaac Asimov. According to his autobiography In Memory Yet Green, Asimov coined the name in imitation of UNIVAC, an early mainframe computer...

) has assigned Chase, who hoped to pursue neurophysiology, to gravitational engineering so he can aid in the military engineers' efforts to harness the energy of the Neutron Star (hence the name Energy Planet). Upon meeting Dr. Donald Gentry on his first day there, Chase learns that people have experienced hallucinations under the Dome.

Part Two: Chase meets the Insects and converses with them.

Part Three: Chase convinces the Commander to respect the insectoids.