Jommy Cross is a Slan, (condensed from Samuel Lann, the discoverer or creator of the subspecies), a mutant gifted with golden tendrils that give him telepathic abilities, stronger, smarter and faster than normal humans, and blessed with remarkable recuperative abilities. Which sounds really cool, but Jommy has a couple of handicaps. One, he's only nine years old, and thus only superhuman in proportion to normal nine-year-olds. And it just so happens that the normal humans hate all Slan and are determined to wipe them out.
In the first chapter, Jommy's mother sacrifices herself to give Jommy the chance to escape. Jommy is then taken in by the loathsome but calculating "Granny", who plans to have the boy steal for her with his inhuman abilities. Shortly after this, Jommy runs into people who detect to his psychic abilities as Slan—but have no tendrils or telepathic abilities of their own. Making contact turns out to be a mistake, as the Tendrilless hate both humans and the True Slan.
Now hunted by both the humans and the Tendrilless, Jommy must hide for years until he can come into his full powers and claim the scientific wonders that are the legacy of his father.
Meanwhile, Kathleen Layton, who is as far as she knows the last Slan living in captivity, is being raised in the palace of Kier Gray, the President of Earth. Supposedly, he's only keeping her alive for scientific study, and treats her coldly, but he also intervenes each time Kathleen is about to be sentenced to death. Very puzzling.
Eventually, Jommy and Kathleen do meet, but don't stay together very long before disaster strikes. Jommy goes on to more adventures before finally being captured by the Tendrilless on their secret Mars base. Escaping, Jommy then speeds to Earth for a final confrontation with Kier Gray, and a series of startling revelations that change everything!
While Slan was not van Vogt's best work, it was exciting, full of intriguing ideas, and caught the imagination of science fiction fans of the day. Mocked and persecuted for their choice of reading matter, SF fans identified with the highly intelligent Slan. "Fans are Slans" became a rallying cry for a certain segment of fandom.
In 1984, A.E. van Vogh started a sequel to Slan, but was unable to complete more than an outline and partial draft before he was struck by Alzheimer's disease. After his death in 2000, his wife Lydia and Kevin J. Anderson finished the book and it was realeased in 2007 as Slan Hunter.
Slan Hunter begins only twenty-four hours after the end of the previous novel, when disaster after disaster strikes before Jommy and his allies can use their newfound knowledge to prevent it. Most of the major characters return, along with a new viewpoint character, Anthea Stewart, a seemingly ordinary woman who has just given birth to a Slan baby, marking her and the child for death.
The story continues the breathless pace of its predecessor (with perhaps a bit more lull to explain some of the backstory) and while it ties up most of the loose ends, ends with a Cliffhanger that was obviously meant to be a Sequel Hook.
Tropes seen in Slan and Slan Hunter include:
- Applied Phlebotinum: The super-science of the Slan, so advanced that normal humans are unable to reverse-engineer it.
- Brainwashed: Jommy learns how to use his powers to hypnotize humans and Tendrilless, and even induce long-term personality changes. He uses this to turn Granny from a greedy, evil alcoholic into a sweet but doddering old lady, and it's suggested that this might be a solution to the hatred of the humans if it can be done to the masses. In the sequel, Granny turns out to be not quite so brainwashed after all, reverting to her greedy, cantankerous personality but retaining basic humaneness.
- Exotic Extended Marriage: Slan have a tradition of multiple partners.
- Fantastic Racism: Humans towards the Slan, and the Tendrilless towards both humans and True Slan. (They call the latter "snakes.")
- I Was Quite a Looker: Granny used to be a famous and beautiful actress, but aged very badly, being reduced to a rag-and-bone woman.
- Kung Fu-Proof Mook: Some of the human Slan Hunters have learned to shield their minds, making telepathy nigh-useless against them.
- The Mole: The Tendrilless have these all over the place.
- One-Word Title
- Parental Abandonment: Jommy's father was killed before Slan begins, and his mother is slain in the first chapter. Kathleen has been led to believe that her parents were both murdered by the Slan Hunters, but Kier Gray is actually her father.
- Planet Baron: Kier Grey is described as this, and proves it by murdering his entire advisory council in the first thirty pages.
- Psychic Powers: Slan are telepathic, and can use hypnotism or illusions to influence weaker minds.
- Scarpia Ultimatum: Jem Lorry offers to help Kathleen not die—if she'll bear his children. The sequel reveals his actual motivation for the offer.
- Self-Made Orphan: Jem Lorry, once he learns the truth about his heritage.
- Zeerust: The future looks suspiciously like Depression-Era New York (to the point that in the 1940 edition, one of the bad guys drove a Studebaker.)
- In both versions of the story the villains inexplicably carry revolvers, despite more advanced weapons existing even when the book was written in the 1940s.