FIRSTBORN concludes the “Time Odyssey” trilogy - with the blend of hard scientific speculation, gripping narrative and cosmic sense of wonder that always marked Clarke's science-fiction novels.

The Firstborn is the name given to an incomprehensibly advanced civilisation, nearly as old as the Universe. They were behind the black monolith in 2001: A Space Odyssey, and although their intentions were unclear then, by the year 2069, when Firstborn opens, we know they are bent on exterminating the human race. The latest threat is a “Q-bomb”, containing the same dark energy (“quintessence”) that fuelled the Big Bang at the beginning of time, on course to collide with Earth at Christmas, 2070, and impervious to anything we can throw at it.

The bomb's technology is beyond the scope of human understanding, but perhaps the alien artefact known as the Eye, left behind on every world marked for destruction, holds the key. With help from Athena (an Artificial Intelligence), and a hint from the sole survivor of another intelligent race destroyed by the Firstborn, it begins to seem that the Q-bomb might be outwitted, and humanity lives on.

The story races along from Earth to Mars and back into alternate history time-lines on the patchwork re-creation of Earth known as Mir, with frequent pauses to discuss the technology of space elevators, telescopes, solar sailing, the exploration of Mars, and so on. There are weaknesses - the characters are paper-thin, there are almost more digressions than plot - but it's an enjoyable read.

Acacia begins like many epic fantasies with a peaceful kingdom threatened by sinister forces, but it quickly unfolds into something far more complex.

King Leodan Akaran is a benevolent ruler and loving father - he's also a drug addict who would like to forget how his children's inheritance was secured through treachery and murder. The attacking Mein, although brutal, become more sympathetic when we learn of the exile and horrific curse laid on them by their ancient enemy. And regardless of whether Mein or Akaran sits on the throne, the empire's economy is still based on a monstrous bargain, by which a quota of human slaves are shipped beyond the limits of the Known World in exchange for Mist, a highly addictive drug.

David Anthony Durham has won acclaim for his historical novels, and brings his knowledge of the past and other cultures to create a rich and compelling world on his first foray into fantasy. His skilful storytelling, depth of characterisation, and an ability to unsettle reader expectations is reminiscent of George R.R. Martin, but his is a distinctive new voice.

Firstborn by Arthur C. Clarke and Stephen Baxter
Gollancz, £16.99; 304pp Buy the book here

Acacia by David Anthony Durham
Doubleday, £12.99; 592pp Buy the book here

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