Ray Stevenson and Mekhi Phifer are the latest names to join futuristic adventure Divergent.
The GI Joe: Retaliation actor, who also stars in hit TV series Dexter, is to play Abnegation's faction leader Marcus Eaton in the big-screen adaptation of Veronica Roth's best-selling novel, while Mekhi is portraying a character known as Max.
Kate Winslet is already on board as rival Erudite leader Jeanine Matthews, alongside Shailene Woodley as Tris, a 16-year-old girl living in a dystopian futuristic world where society is divided into five areas, each representing a particular virtue, in Neil Burger's film.
"It's very exciting. The people who have brought us The Hunger Games and Twilight are doing this movie, and... Kate Winslet is attached," Ray told Red Carpet TV.
Jai Courtney, Zoe Kravitz, Ansel Elgort, Theo James and Maggie Q are also confirmed to appear in the film, which has started production in Chicago and is scheduled for release in 2014.
Divergent - the first book in the series - is apparently being planned as the first in a potential trilogy of movies, to follow in the footsteps of The Hunger Games and Twilight.
Ray, who plays Firefly in Jon M Chu's GI Joe follow-up and is seen as Ukrainian head gangster Isaak Sirko in Dexter, will reprise his role as Asgardian warrior Volstagg in the Thor sequel, The Dark World, which also stars Chris Hemsworth and Tom Hiddleston.