It is a very long time since I read Slan, one of the classic novels of the "golden age" of the 1940s which had a huge impact at the time, so when I learned that a sequel had been written I decided to read both.
Slan is a far-future story set on Earth (with scenes on Mars towards the end) in which enhanced humans called slans, featuring extended lifespans, inhuman strength, speed and intelligence, plus the ability to read minds with the aid of fine "tendrils" in their hair, are being persecuted close to extinction by the rest of humanity. The hero of the story is Jommy Cross, a young slan whose mother is killed in the first scene of the tale. Captured by an old woman who uses him as a thief, he grows up and discovers the secrets of advanced science left to him by his father, which enable him to construct formidable technological devices. He also discovers that there is a secret race of tendrilless slans who cannot read minds but whose abilities have allowed them to monopolise air travel - and to clandestinely develop space travel as well. His long search to discover other true slans and to understand why humans and the tendrilless slans hate them so much fills the rest of the novel.
The story is very much of its time and is dated in style as well as scientific understanding - Mars is portrayed as having a breathable atmosphere, for example. The ending is also rather rushed, consisting of a long infodump in which Jommy is told the answers to many of the questions which have troubled him. Despite these flaws the relentless pace and unrestrained imagination drag the reader along, as usual with a van Vogt tale.
In the 1980s the author began to write a sequel, but only got as far as the story outline and a hundred or so pages before he stopped. Kevin J Anderson was eventually given the job of completing the tale and the result, Slan Hunter, was published in 2007. This picks up when Slan left off, concluding the tale of Jommy's search to discover the truth about the slans of both varieties, with all loose ends neatly tied up. I was amused to notice a couple of retrospective explanations for peculiarities in the original. Mars has a breathable atmosphere, we are told, because a thousand years earlier humanity had bombarded the planet with ice comets, algae and bacteria in a massive terraforming exercise, resulting in the return of surface water, a thick atmosphere and warmer temperatures. Also, the remarkable similarity of human culture and technology to 1940s USA is explained by the devastating effect of the slan wars, so that "even now our society has returned only to the equivalent of the United States of America back in the 1940s…some of the cultural similarities to that period are quite striking." Indeed they are!
The new book remains very faithful in style to the original. This also applies to the ending, including as it does some sudden and unexpected revelations. I have to say that this is not necessarily a good thing, unless you think that van Vogt's style can't be improved on. I found that I am much more inclined to be tolerant of technical and stylistic shortcomings in a 1940s book than I am in a 21st century one. This is very unfair of me since Anderson evidently worked hard to match the original, but from my perspective he can't really win: his deliberate pastiche of 1940s style doesn't particularly appeal to me, but a more modern approach would probably have infuriated van Vogt's more devoted fans. So it goes…