'The Expanse' Confirms the Return of Clarissa Mao in Season 5

Four returning cast members have been announced for The Expanse Season 5, including one returning character that could have big implications for upcoming episodes.

On Tuesday, Deadline announced that three cast members of The Expanse will be more than recurring characters in the upcoming Season 5 and have been promoted to series regulars. The first two will be obvious to watchers of The Expanse Season 4, which set up the characters as major threats in a finale cliffhanger.

Marcos Inaros in 'The Expanse' Season 4. Amazon Studios

Keon Alexander (NCIS) will return to The Expanse Season 5 as Belter terrorist leader Marco Inaros. Introduced in Season 4, the Belter pirate has refused the fragile peace between Earth and the working class Belters. Responsible for a string of deadly attacks, Inaros talks his way out of his own execution and lays a trap for reformed pirate captain Klaes Ashford (David Strathairn).

Jasai Chase Owens (The Deuce) was seen only briefly in the most recent season of The Expanse, but is likely to play a much larger role in Season 5. Owens plays Filip Inaros, son of Marcos and Rocinante engineer Naomi Nagata (Dominique Tipper), from whom he's been estranged his entire adult life.

Together, the father-son Inaros duo represent the greatest threat to Earth at the beginning of The Expanse Season 5. In the final episode of Season 4, Marco launched an attack on the United Nations, using Martian stealth technology to mask Belter asteroids and fire them toward Earth. Should they hit their target, the Earth government may soon be in as much chaos as Mars. Just as dangerous, a Belter faction attack on Earth could be casus belli on the Belters who are currently well-positioned to colonize the worlds opened by the Ring gates at the end of Season 3.

But while the father-son Inaros duo represents the chaos coming in The Expanse Season 5, it's another returning cast member whose addition opens up new plot possibilities for the upcoming season. Nadine Nicole (Casual) will return as Clarissa Mao, the daughter of industrialist and recurring Expanse character Jules-Pierre Mao.

Sporting deadly combat enhancements, Clarrisa Mao seeks revenge in Season 3. Amazon Studios

A business dynasty, the family owners of Mao-Kwikowski Mercantile were some of the most central and dangerous power factions in the solar system in earlier seasons of The Expanse. Through corporate subsidiary Protogen, Jules-Pierre was behind early and deadly experiments into the alien protomolecule. Clarissa was introduced in The Expanse Season 3 as an ambitious potential heir perpetually under-appreciated by her father. Using the alias Melba Koh, Clarissa infiltrated the mission to the protomolecule Ring and eventually played a central role in the unlocking of the Rings.

Will Clarissa be allied with Mao-Kwikowski Mercantile in the coming season, or has she left that life behind? Unseen in The Expanse Season 4, it's unlikely the system-spanning mega-corporation has sat idly by as everyone else positioned themselves to take power and colonize new worlds.

Lily Gao will also return in The Expanse Season 5. Gao played U.N. politician Nancy Gao in the fourth season and now in the fifth, will be Secretary-General of the United Nations, having won an election against Chrisjen Avasarala (Shohreh Aghdashloo).

Based on The Expanse novels by James S. A. Corey, the series premiered its first season on Amazon Prime Video in December after its Syfy cancellation. A release date for Season 5 of The Expanse has not yet been announced.