It is only natural that attention will focus on this, the final - barring any lost or secret manuscripts discovered in the future - novel to bear the name of Terry Pratchett in terms of one-half of its authorial credits.

But it is, of course, a collaboration, the fifth in a series that was conceived by Pratchett and Stephen Baxter over dinner in 2010, three years after Pratchett announced to the world that he was suffering from early-onset Alzheimer’s.

Pratchett and Baxter - himself a veteran science fiction writer, one of Britain’s brightest and most acclaimed - completed the series in three years, with the publication of the first, The Long Earth, in 2012. There has been one novel released a year with this, the final volume, coming a year after Pratchett’s death in March 2015.

It’s a very different beast to those used to Pratchett’s humorous Discworld fantasies - a hard, high-concept science fiction series based around the central conceit that our world is but one of an infinite number of parallel Earths, strung out like a multi-dimensional string of pearls.

The first book detailed the discovery of this multiverse and mankind’s hesitant exploration of these worlds that are geographically identical to ours but with no humans. Subsequent sequels explored the multiple Earths and beyond.

Terry Pratchett: A career in quotes Show all 13 1 /13 Terry Pratchett: A career in quotes Terry Pratchett: A career in quotes “Inside every sane person there’s a madman struggling to get out” –The Light Fantastic Pratchett photographed in 1990 Corbis Terry Pratchett: A career in quotes "We Pratchetts are a feisty bunch" Pratchett with his daughter Rhianna at home in 2009. Rhianna is now a writer in her own right and has written the storylines to video games such as Tomb Raider and Overlord Rex Features Terry Pratchett: A career in quotes "It occurred to me that at one point it was like I had two diseases - one was Alzheimer's, and the other was knowing I had Alzheimer's" Terry Pratchett delivers a petition on behalf of the Alzheimer's Research Trust calling for an increase in government funding for dementia research in 2008 Getty Images Terry Pratchett: A career in quotes "Imagination, not intelligence, made us human" Terry Pratchett with his double-row of six computer screens in 2009 George Wright Terry Pratchett: A career in quotes “If you don’t turn your life into a story, you just become a part of someone else’s story” Pratchett was awarded an OBE in 1998 PA Terry Pratchett: A career in quotes “Sometimes glass glitters more than diamonds because it has more to prove” - The Truth Terry Pratchett launches his 25th novel of the 'Discworld' series, 'The Truth' in 2000 Corbis Terry Pratchett: A career in quotes “Time is a drug. Too much of it kills you” In 2007, the year he announced he had Alzeihmer's Getty Images Terry Pratchett: A career in quotes "You can't ask a fantasy writer not to want a knighthood" Receiving his knighthood in 2009 AFP PHOTO/Ian Nicholson/POOL Terry Pratchett: A career in quotes "Life doesn't happen in chapters - at least, not regular ones" Pratchett at home in 2009 Rex Terry Pratchett: A career in quotes “The trouble with having an open mind, of course, is that people will insist on coming along and trying to put things in it” Pratchett at the world congress of the World Federation of the Right-to-Die Societies in Zurich, 2012 Corbis Terry Pratchett: A career in quotes “Inside every sane person there’s a madman struggling to get out” Attends the South Bank Sky Arts Awards in 2012 Getty Images Terry Pratchett: A career in quotes "Insanity is Catching" Pratchett won the Bollinger Everyman Wodehouse Prize at the Telegraph Hay Festival, pictured with Snuff the pig in 2013 Getty Terry Pratchett: A career in quotes “People don't alter history any more than birds alter the sky, they just make brief patterns in it” - Mort Campaigning for Dementia Friends in 2014 PA

Although there are a core cast of well-rounded characters, including central protagonist Joshua Valiente, one of the first to learn how to “step” between the worlds, and Lobsang, a Tibetan motorcycle repairman who has been reincarnated as an artificial intelligence computer (one guesses that to be a very Pratchettian touch) the series has always seemed less about the people and more about the sense of wonder of good, old-fashioned science fiction.

More than that, it’s about exploration and discovery, and even rediscovery - if we found an Earth identical to our own but uninhabited and unspoiled, would humanity do things differently, or just make the same old mistakes?

The Long Cosmos, is the final book in the series and as such, not the best place to start if you’re unfamiliar. It involves a widening of the scope into deep space and the existence of other, older intelligences.

This book and the series as a whole provides polished sci-fi adventure - belying, as Baxter writes in his introduction, the fact that it was written quickly: “Time was not on our side.” It might not be as memorable for many people as the cherished Discworld, but nevertheless, it is a fine and fitting testament to the work of one of our greatest and much-missed writing legends… and a reminder that in the likes of Stephen Baxter, British science fiction remains in safe hands.