Three more actors have come aboard for Paramount and Skydance's Terminator: Genesis film, joining an already quite full cast.

Mad Men actor Michael Gladis, Sandrine Holt and Byung-hun Lee are the latest additions to the film, according to The Hollywood Reporter. Gladis' and Holt's roles have not been announced.

South Korean actor Lee, who appeared in G.I. Joe: Rise of Cobra and the sequel, is reportedly set to play an important role in the film, but any further details are being kept under lock and key.

The three join the recently cast Dayo Okeniyi and Arnold Schwarzenegger, along with Emilia Clarke, Jason Clarke, Jai Courtney and J.K. Simmons.

Okeniyi was cast to play the son of scientist Miles Dyson, who was involved in the creation of Cyberdyne Systems and also killed in Terminator 2: Judgment Day.

Genesis is meant to be the start of a standalone trilogy, but help tie back to the original films. Though Schwarzenegger has aged much since he last starred in the films, his appearance will be explained in the film.

Emilia Clarke is set to play Sarah Connor, Jason Clarke will be John Connor and Courtney plays Kyle Reese.