‘The 100’ Season 5 Spoilers: Which ‘Shadowhunters’ Actor Will Appear In Finale?

“The 100” Season 5 won’t be premiering until April, but the show is already working on what might be its final run.

The post-apocalyptic sci-fi series will feature a slew of guest stars, and the latest to join the cast is “Shadowhunters” actor Shannon Kook. The “Degrassi: The Next Generation” star will appear in the finale episode of “The 100” Season 5, Deadline reported.

Kook will reportedly play a character named Lucas, although the rest of the characters are being kept under wraps by the show. Kook’s character may also play a big role as the actor has signed on with the option of playing a series regular in “The 100” Season 6 if the show gets renewed.

Kook isn’t the first “Shadowhunters” star to join the cast of “The 100.” Lola Flanery, who played the Seelie Queen in the Freeform series, played new character Madi in the previous season, according to Digital Spy. One former “The 100” star also joined the “Shadowhunters” universe, with Chai Hansen being cast as fan favorite character Jordan Kyle in the Freeform series.

As for the plot, the upcoming season of “The 100” will pick up six years after a second nuclear apocalypse destroyed the world. Season 5, according to showrunner Jason Rothenberg, will serve as a “reboot” for the show.

The time jump will not just bring new challenges and twists, but it also means fans of the show will be seeing several new characters next season. Two of the characters fans will get to know in Season 5 are adrenaline junkie Zeke Shaw (Jordan Bolger) and a new villain to be played by William Miller.

Miller’s character, Robert McCreary, is connected to the Eligius Corporation prisoner transport spaceship that returned to Earth in “The 100” Season 4 finale, according to TV Line. He is described as a “mysterious prisoner” who was once a “former enforcer from a powerful crime syndicate.”

"His ruthless, violent methods make him a formidable antagonist to our heroes,” his description read.

Guest Tasya Teles has also been given a bigger role to play in “The 100” Season 5 as she has been promoted to series regular. Meanwhile, Eliza Taylor, Christopher Larkin, Bob Morley, Marie Avgeropoulos, Lindsey Morgan and Paige Turco will all be reprising their roles in the upcoming season.

“The 100” Season 5 premieres on The CW on Tuesday, April 24.