Originally serialized in the pages of the pulp magazine Astounding in 1940 before being slightly revised and published in book form in 1946, A.E. van Vogt's Slan is an exciting thriller with subtle political overtones that are even more manifest in the present day.
Van Vogt starts off the book with the main storyline of Jommy Cross, a descendant of a genetically-enhanced race of humans called "Slans", created by a fanatical scientist Samuel Lann in the late 21st century. The Slans, who can read and control minds and can be identified by tendrils on their scalp, briefly conquered the Earth before being overthrown in a massive world war. Now, some four or five hundred years later (van Vogt doesn't quite clarify the timeline), humans chase down and kill any Slans (like Cross' parents) they can find, while "tendrilless" Slans hide within the community and manage to construct, under the Earth goverment's very noses, a space fleet capable of flying to Mars and other planets. These Slans also hate any of their members who have tendrils (like Cross) and are perfectly willing, despite their obviously advanced scientific knowledge, to wipe out scores of innocent human bystanders just to get Cross, who has his own agenda to carry out.
Cross has been entrusted by his late parents to find a concealed weapon created by his father to assassinate the Earth dictator Kier Gray and allow the Slans to lead (come out) normal lives unafraid of any threat. Meanwhile, Gray must keep his Slan ward, Kathleen, from being assassinated herself by his secret police head John Petty. Everything comes together in a powerful climax, although the Big Revelation from one of the characters does seem to come out of left field at first. (Rereading the novel, there are subtle hints to be found revealing this character's true nature.)
For a novel first written over sixty years ago, Slan, taking into account the scientific and social background of the period it comes from, almost reads like a work by an author from this generation. The novel's underlying themes can still be interpreted on a vast number of levels, from frantically-paced pulp fiction to political and social allegory. The Slans themselves can be viewed as representing any oppressed group of persons from the past and present (African-Americans, Jews, Gays), and the political manipulation of the Slans and humans (both are whipped into mob mentality/hatred based on fear and ignorance) by their leaders has historical antecedants from the past and present. In fact, the protagonist Cross himself isn't above using a little manipulation (via mind control and hypnotism) of his own, but the sincerity of Cross's cause, and some of the less-than-nice people he has to "control", cancels out any doubt about his intensions.
But van Vogt also wants to entertain his audience as well as make them think, and he doesn't stint on the thrills. There are LOTS of hair-raising, exciting moments (such as Cross's original accidental discovery of the Slans' rocket bay), including spaceship chases (!), plus cool gadgets galore. And while characterzation isn't quite multifaceted or complex (the good guys are tolerant and noble, the bad guys evil and ignorant), you'll still find yourself personally involved with the characters' plights thanks to van Vogt's imaginative and fascinating writing style and plotting. (And boy, with just a few changes to update the science and technology described in the book -how do the Slans fly to Earth and back without being detected?- Slan would make a great movie!)
Slan can be reserved online here.
In 2007, a belated sequel, begun by van Vogt and completed by Kevin J. Anderson, Slan Hunter, was published. That can be reserved online here as well.
Related link: The Slanology site.