Game of Thrones will be adding a recurring character to its regular cast, and offers a look behind the scenes with a new production video.

Game of Thrones may have culled the ranks of its regular characters somewhat in its third season, but the epic HBO fantasy still boasts one of the largest casts on television. Now news comes that a recurring cast member will be promoted to a series regular in the upcoming season.

Entertainment Weekly has revealed that actress Nathalie Emmanuel will become a regular cast member in the unconfirmed-but-presumed Game of Thrones season 5. Emmanuel joined the cast in season 3 and plays Missandei, a young slave freed by Daenerys Targaryen, who serves as translator, scribe, and friend to the would-be queen of Westeros.

In a similar move, actor Michael Huisman has also signed on to become a series regular in season 5. Huisman will make his debut in Game of Thrones season 4 in the role of dashing sell sword Daario Noharis – another important figure in Daenerys’ story line. Huisman will replace Ed Skrein, who originated the role in season 3.

Meanwhile, HBO has released a new production video from behind the scenes on Game of Thrones season 4. The new video introduces viewers to Deborah Riley, the new production designer on the upcoming season, who is taking over the reins from Gemma Jackson.

The video offers several glimpses of new scenes. Among the footage is Daenerys, ruling Meereen in a cut-out gown, Jon Snow stalking through Castle Black, and Cersei dressed in an uncharacteristically dark dress. Also included are two scenes which readers of A Song of Ice and Fire will instantly recognize – Jaime, Brienne, and a sword, and the long-awaited wedding of King Joffery to Margaery Tyrell.

The new video makes it especially clear just how much work and care is invested in Game of Thrones. The scope and scale of the production, and the intricate attention to detail are unparalleled in television production. “You don’t get a better sandbox to play in,” Riley says. “It’s like ‘Extreme Art Department!'”

Game of Thrones season 4 will premiere on April 6 at 9:00 p.m. on HBO.

What are you most excited to see in ‘Game of Thrones’ season 4?