For episode eighteen we go back to Terry Pratchett's science fiction beginnings as - in the evening between the two days of the 2019 Speculate festival - author Will Kostakis joins us to talk about Pratchett’s standalone 1976 novel, The Dark Side of the Sun!

Dom Sabalos is about to become Chairman of the planet Widdershins when he is messily assassinated. Well...mostly. When he survives against all odds, he discovers his death had been predicted using probability math. The same science also predicts he will discover Joker's World, the mysterious home of the vanished ancient species thought to have laid the foundation for all intelligent life. Dom sets out to fulfil his destiny with his alien mentor Hrsh-Hgn, his new robot, Isaac, and a strange, lucky creature from his homeworld's swamp.

Filled with references and homages to prominent science fiction authors like Larry Niven, Isaac Asimov and Frank Herbert, The Dark Side of the Sun is the first of Pratchett's two early science fiction novels. (We’ll get to the other one, Strata, in fifty episodes’ time.) It features the first appearance of many names and concepts he would later recycle for the Discworld. It's a short, fast-paced book with big ideas - not least Pratchett's own take on the classic sci-fi trope of a vanished, ancient precursor species known only through mysterious artefacts. But does it work? Is this an early sign of genius, or a run-up for someone who needed more time to come into his own? We'd love to hear from you! Use the hashtag #Pratchat18 on social media to join the conversation.

Guest Will Kostakis is a writer and award-winning author. He's written many short stories and four novels, all for young adults, including The Sidekicks and The First Third. As mentioned in the episode, his first fantasy YA novel, Monuments, will be released in September 2019. You can find out more about Will and his work at willkostakis.com, or follow him on Twitter at @willkostakis.

You can find the full show notes and errata for this episode on our web site.

(This episode was released just before Liz and Ben appeared at Nullus Anxietas 7, the Australian Discworld Convention, on April 13 and 14 2019! The live episode they recorded at the convention is available in the podcast feed as #PratchatNA7, “A Troll New World”.)

Next month it's back to the Discworld as we crank up the volume and rock out with Death! Yes, we'll be reading Soul Music, so get your questions in via social media by mid-April using the hashtag #Pratchat19.