Published in 2003, Diamond Dogs, Turquoise Days collects two sci-fi novellas by British author Alastair Reynolds. While both are set in his Revelation Space universe, they are only distantly connected with other works by Reynolds, and can be read in isolation. Both "Diamond Dogs" and "Turquoise Days" are set in the 26th century, when humans have spread to numerous planets and in addition to encountering alien races, have also begun to radically alter their own minds and bodies. Separated by enormous distances which only "lighthugger" starships can cross, human worlds develop radically different cultures, while advanced technologies threaten to upend whole civilisations.
"Diamond Dogs", named for the 1974 album by David Bowie, is the first story in the compilation. It begins on the human world of Yellowstone, where a man named Richard Swift is contacted by an old friend he believed to be dead. Roland Childe asks Swift and a number of other carefully chosen individuals to travel with him to the uncharted planet he has named Golgotha, there to explore a mysterious alien structure dubbed the "Blood Spire".
With this story, Reynolds is clearly riffing on the fairly familiar theme of the deadly maze. The Blood Spire is, like the titular structure in the 1997 film Cube, filled with lethal traps and requires an advanced understanding of mathematics to have any chance of escaping. The author works through the grisly ramifications of the tale - his characters become obsessed with defeating the tower, which is seemingly alive and even actively cruel. The technology available to them, and the mind-bending challenges of the Blood Spire, encourage Swift to gradually abandon his humanity in his fanatical quest until finally, the story's title makes sense.
"Diamond Dogs" is a wonderfully brisk and entertaining story. While based on a familiar theme - the similarities to Cube in particular are striking - Reynolds' writing provides all the enigmatic developments and grisly incidents to keep the pages turning quickly. The ideas about obsession and the depiction of high technology that can warp the mind and body give a pulpy and sometimes gruesome tale an intelligent underpinning. Overall, the effect is similar to that of a sci-fi B-movie with a smart script that you want to watch over and over again.
"Turquoise Days" is a tale of two halves, named for a song by Echo and the Bunnymen. The first half, in particular, is much more of a slow burn than "Diamond Dogs". Sisters Naqi and Mina are young researchers on the isolated ocean planet Turquoise. They are small-fry scientists helping to study the Pattern Jugglers, aquatic micro-organisms with the ability to re-write the human brain. Against all protocol, the sisters swim with the creatures and commune with the many human and alien intelligences that have done so before - an experience that Mina does not survive. At least, not in her original form.
Two years later, Turquoise is visited by the Voice of Evening, the first lighthugger to visit the backwater planet for a century. Now a more senior researcher, Naqi finds herself embroiled in an incident with political ramifications far beyond Turquoise, and which relates to a malign presence both she and her sister encountered during their fateful swim.
While the first half of the story can seem a little uneventful, and a world away from the bloody incidents of "Diamond Dogs", this second story delivers very strongly in its latter half. Many small details from the opening prove crucial in the exciting climax of the story, which rattles along at a tremendous pace and sees the fate of the whole planet hanging in the balance. Again, the terrifying implications of technology are a major theme, this time joined by the terrifying implications of a creature that can invade a human and re-write their brain.
Both of the stories in Diamond Dogs, Turquoise Days are extremely entertaining examples of Alastair Reynolds' particular brand of science fiction. That Reynolds manages to subtly link the two stories together, and uses them as a window into specific elements of his wider universe, makes them even more appealing. Expect to race through these novellas, and be left wanting more. Fortunately, there's the whole of the Revelation Space universe to explore.
Read my review of Reynolds' more recent novella, Slow Bullets (2015)