‘Game of Thrones’ Season 4 Casting: Why Is ‘Sherlock’ Star Mark Gatiss Character Tycho Nestoris Introduced Early In Episode 1?

"Game of Thrones" season 4 has new casting news: "Sherlock" actor Mark Gatiss will appear as Tycho Nestoris in episode 1 of "Game of Thrones" season 4.

Winter is Coming has discovered that Mark Gatiss will be playing the role of Tycho Nestoris; this information was revealed on the "Sherlock" actor's official CV, Hypable.com reports.

According to the website: "Tycho Nestoris is a banker representing the Iron Bank of Braavos, who travels to Westeros in the 'A Song of Ice and Fire' saga in order to reclaim the money which the bank has lent King's Landing."

However, it seems that Gatiss will only make a guest appearance in "Game of Thrones" season 4, and will not have a major role this season. According to Hypable, Gatiss was able to complete his scenes only a few days after filming started at his location, and IMDb has the actor listed as only appearing in season 4, episode 1 of "Game of Thrones."

ScreenCrush.com reports that Gatiss was announced for an upcoming role in the series back in mid-July, but only now have details of the actor's role in season 4 been announced.

Interestingly, Tycho Nestoris doesn't appear in the saga until George R.R. Martin's fifth book, "A Dance With Dragons," while HBO's adaptation continues moving through book 3, "A Storm of Swords," with a few elements from book 4, "A Feast for Crows," Screen Crush reports. Some are wondering why Tycho Nestoris is being introduced earlier in the series.

"Game of Thrones" season 4 will premiere in the spring of 2014.

Mark Gatiss will also reprise his role as Mycroft Holmes in "Sherlock" series 3, which premieres later this year on BBC.