Like most of van Vogt's longer works, it is a fix-up, comprising three shorter pieces written over a period of more than twenty-five years: Despite sharing authorship of the last story (which was also collected in 1971's More Than Superhuman), Schmitz was not credited for the overall novel.

No dates are provided, but "Asylum" is set about a hundred years after the discovery of practical space travel, with colonies dotting the Solar System and the transit time from Earth to the Jovian moons being about a month.

In "Asylum," higher cognition grants advanced but non-paranormal capabilities such as extremely rapid reflexes, lie detection, multicameralism, and the ability to control lesser minds through non-verbal hypnotic suggestion; the follow-up stories contain explicitly psionic powers such as telepathy and teleportation.

Raw intelligence is apparently a sharp social differentiator in Galactic society; the Observer is noted to be psychologically tortured by an awareness of his own relative inferiority, and he and his daughter both treat the term "Klugg" as a slur.

The Dreegh are essentially vampires–the last remnants of a group of galactic humans whose physiology had been changed after they were accidentally irradiated by an abnormal sun a million years earlier, making them immortal but requiring regular infusion of blood and "bio-electric energy" to survive.

However, a shock brought on by the imminent death of Patricia Ungarn (whom Hanardy secretly loves) "awakens" him; he stops time, saves her, cures the Dreegh, and teleports their spaceship six thousand light years away.

Hammond, who is - along with several other Research Alpha senior staff - a secret observer from the galactic civilization, becomes concerned with the experiment and tries to detain Ellington, but she is determined to receive the full course of Point Omega treatments and uses her powers to evade him.

The 1977 fixup made only minor changes to the plot, such as moving forward the origin of the Dreegh tribe from a million years ago to only a thousand; the only significant addition to the narrative was a short passage interpolated into the penultimate chapter of "Research Alpha," in which Ellington informs Hammond that the Great Galactic she is going to meet in space is in fact "Asylum's" protagonist William Leigh.