The producers of 'Downton Abbey', ITV and Carnival Films, have just revealed some details about a special Christmas episode that's going to air this year. They've announced that fans of the show can expect to see two new guest star cast members appear in the 2-hour episode.

Alun Armstrong, of 'Braveheart' and 'Sleepy Hollow' fame, is one of the new guest stars and will be taking on the role of Sinderbys' butler, who's name is Stowell.

The second guest star is BAFTA Award nominee Jane Lapotaire who's known for her roles in 'Shooting Fish' and 'Blind Justice'. She will be taking on the role of Princess Irina who is the wife of Prince Kuragin, played by Rade Sherbedgia.

Stepping into some spoilers for the episode, viewers will see the whole family get together during one of the most exciting events of the year, grouse hunting season. In the episode, Rose's father-in-law, Lord Sinderby has apparently rented out Brancaster Castle in Northumberland to take advantage of the occasion.

While all seems well with the Crawley family and their time spent at the castle, the same cannot be said for Stowell, who knows about all the scandalous secrets that threaten the joyous season. It will become clear that while everyone is getting to know each other better, especially with the addition of the new faces, tensions might become too intense to handle.

Meanwhile, at the Downton fort, Anna considers her options as she remains locked up behind bars, as Bates desperately tries to exonerate her.

On a side note, Baxter and Mosely will scheme up a plan together, as Carson and Mrs Hughes think about a possible business venture.

Seeing as this episode of 'Downton Abbey' is the Christmas special, it's no surprise that many of the characters in the series will be showcased. Within the span of two hours, which is roughly the length of the entire special, the list of characters that will appear on screen include:

Maggie Smith, Michelle Dockery, Elizabeth McGovern, Jim Carter, Penelope Wilton, Phyllis Logan, Laura Carmichael, Lily James, Allen Leech, Brendan Coyle, Joanne Froggatt, Lesley Nicol, Sophie McShera, Robert James-Collier, Kevin Doyle, Raquel Cassidy, Sue Johnston, Jeremy Swift, Douglas Reith, Fifi Hart, Zac and Oliver Barker, and Hugh Bonneville.

The 'Downtown Abbey' Christmas special is set to air on Christmas on ITV.