Downton Abbey had certainly gained a huge following over its past 5 series, and there is a holiday or Christmas special on the way that could create quite a stir amongst its viewers.  The special will feature guest stars Alum Armstrong, Jane Lapotaire, and Matthew Goode, all veteran actors.   

According to The Telegraph, the Christmas special for Series 5 of the British period drama series will take place on Brancaster Castle in Northumberland.  The actual location is Alnwick Castle, which has been featured in the Harry Potter films.  It begins when Lord Sinderby (James Faulkner) rents the location for a "shooting party" for grouse shooting season. 

Stowell, a butler of the Sinderbys, will join the grouse-shooting party.  Stowell is a special guest star, and he is played by Alun Armstrong, who has been featured in the British comedy drama New Tricks, as well as the film Braveheart, playing the Scottish noble Mornay, the betrayer of William Wallace.  Stowell brings a "scandalous secret that threatens to undermine the holiday". 

Another special guest star will be Jane Lapotaire, a very accomplished actress.  Lapotaire will play Princess Irina, the wife of Prince Kuragin (Rade Sherbedgia) as well as the potential love rival to the Dowager countess (Maggie Smith). 

There is another guest star who, according to the Mirror, was spotted filming scenes for the Christmas special, actor Matthew Goode.  Goode is known for his work on CBS drama The Good Wife, as well as the superhero movie Watchmen where he played costumed crimefighter and plotter Ozymandias.  Goode plays the love interest for Lady Mary (Michelle Dockery), who has been denying suitors over the past two series since the death of her husband.  Lady Mary has shunned a marriage proposal from Tony Gillingham (Tom Cullen), and Charles Blake (Julian Ovenden) has possibly given up trying for her affection. 

At Downton Abbey, the servants are taking care of the place with conflicts of their own.  For example, Anna (Joanne Froggatt) faces imprisonment for Mr. Green's murder, and Bates (Brendan Coyle) intends to do something quite drastic to clear Anna's name.  Also, Carson (Jim Carter) and Mrs. Hughes (Phyllis Logan) are considering a business deal of some sort, and Baxter (Raquel Cassidy) and Molesley (Kevin Doyle) are also working on a plan of their own. 

Considering that the supposed main plot of the Downton Abbey Christmas special is about grouse-shooting, it seems like a set-up for an accidental death.  A past episode saw the death of Matthew Crawley (Dan Stevens), and it is not known if there are any sudden departures planned for the holidays this year.