The Expanse season 4 is set to arrive on Amazon within a few months. Some fans were worried the previous season would be the last, especially after Syfy canceled the series. However, loyal viewers went on Twitter and used #SaveTheExpanse, and, a few weeks later, Amazon Prime picked up the series and funded the fourth installment.

The Expanse season 4 will drop on Amazon Prime on Friday, December 13, with all of its 10 episodes available to stream at once. Viewers can also catch up on the first three installments of the series, all of which are currently streaming on the platform. Also, the fourth season wouldn't be the last, as Amazon also renewed the series for a fifth season.

As for who's returning in the upcoming installment, all core cast members in the third season are set to come back. That means we'll see Steven Strait as James Holden, Shohreh Aghdashloo as Chrisjen Avasarala, Cas Anvar as Alex Kamal, Frankie Adams as Bobbie Draper, Wes Chatham as Amos Burton, and Dominique Tipper as Naomi Nagata returning in The Expanse Season 4.

Meanwhile, we're also going to see new faces in the latest installment. Burn Gorman will portray the role of Adolphus Murtry. He is an antagonist who takes over the Ilus settlement by force and rules it with an iron fist. Other new faces include Lyndie Greenwood (as Dr. Elvi Okoye), Rosa Gilmore (Lucia Mazur), Jess Salgueiro (Chandra Wei), Lily Gao (Nancy Gao), and Chai Valladares (Aide Diaz).

At the end of the third season, the world of The Expanse blown wide open by the manifestation of multiple portals, and it served as gateways to other solar systems with habitable planets. While the series has been entirely focused on the political, it's now moving into Space Western territory. Humans are now rushing to colonize other habitable planets and compete over their resources.

The Expanse season 4 will likely adapt Cibola Burn, the fourth novel in the series. Here, the events take place entirely on Ilus, Earth-like planet. But, showrunner Naren Shankar also made it clear the new season won't leave Earth, Mars, and the Belt behind. Moreover, the looming mystery regarding dead alien civilization that created the protomolecule will still be explored in the latest installment.

The most recent trailer of The Expanse season 4 was released during the recent 2019 New York Comic-Con panel. Before that, the series also dropped a trailer during the San Diego Comic-Con, where it revealed the official premiere date and introduced Gorman. Additionally, Amazon dropped a five-minute clip during the event featuring the Rocinante landing on Ilus.