'Leviathan Falls': The 9th and final book of epic 'The Expanse' sci-fi series revealed

Fans of the popular science fiction book and television series "The Expanse" got the first glimpse at the cover of the ninth — and final — book in this futuristic space saga. 

During a 15-minute virtual event streamed live on Crowdcast on Wednesday (Sept. 16), fans asked questions to the writing duo behind the successful series, Daniel Abraham and Ty Franck, who are known collectively as James S. A. Corey. 

These books, published by Orbit, inspired the ongoing television series which first aired on Syfy and premiered its fourth season on Amazon Prime in 2019. The story takes place in a future where humans populate the solar system, and the series follows the crew of the spaceship Rocinante as they deal with interplanetary politics, an alien lifeform and each other. 

The new book will be coming out in 2021 and the audiobook will likely be available on the same date. The first book in "The Expanse" series, "Leviathan Wakes," was published in 2011. 

Related: Rejoice, 'Copeng'! Belter Creole Returns on 'The Expanse' Season 4

Abraham and Franck took time to celebrate the cover artwork of the ninth book, "Leviathan Falls." They praised artist Daniel Dociu and cover art director Lauren Panepinto for the ninth book's look and for the continuity all the book covers in the series have had. 

There is no plan to write any more novels for "The Expanse" after book nine, but there may be more content created for the television series that won't appear in the books, Franck said. 

After that book, the main story ends. But Abraham and Franck did say there is another novella that will be published after "Leviathan Falls," which Franck said "puts a nice grace-note ending on some hanging threads from the series… in, I think, a lovely way."

Related: Best space and sci-fi books for 2020

Orbit will also publish a volume containing all of the series' novellas and short stories in one place.

However, there is "not a chance" that they'll follow the end of the book and TV series with prequels," Abraham said. "Once it's done, it's done." 

Abraham also answered a question about what it feels like to end this long series. 

"This is actually the fourth multi-novel series that I'm bringing into port, and there's always a certain kind of melancholy that goes with that. There's a real satisfaction too, of getting to the end of something this long. This feels like graduating from college," Abraham said. 

Fans also asked the duo if they will collaborate again in the future. They've sold a three-book series to Orbit, they said, but they haven't started working on it yet. Abraham did say that the new S.A. Corey series is a "very different project" than ''The Expanse'' series, and that the upcoming series might be reminiscent of the work from science fiction and fantasy writers like Frank Herbert ("Dune") and Ursula K. Le Guin ("Earthsea"). 

When asked what books inspired them this year. Abraham gave praise to Carmen Maria Machado's book "In the Dream House" (Graywolf Press, 2019), and Franck said that Joe Hill is his favorite living writer. 

Follow Doris Elin Urrutia on Twitter @salazar_elin. Follow us on Twitter @Spacedotcom and on Facebook.