'Game Of Thrones' Season 5 Spoilers: 'Sherlock's' Mark Gatiss To Reprise Role As Tycho Nestoris, Will His Character Connive With Kit Harrington's Jon Snow At The Wall?

Mark Gatiss is returning for the fifth season of "Game of Thrones!"

Gatiss will reprise his role as Tycho Nestoris, a representative of the formidable Iron Bank of Braavos, who first appeared on the show last season in the episode "The Laws of Gods and Men." The 47-year-old British actor is said to be back on the set of the hit HBO fantasy drama series in Croatia next week, Entertainment Weekly reported.

In Season 4, Nestoris and the Iron Bank decided to finance Stannis Baratheon's (Stephen Dillane) army in an effort to take the Iron Throne from the Lannisters, who have fallen into debt with the gold Cersei (Lena Headey) borrowed from the bank, International Business Times reported.

Though Gatiss' role last season was a small one, his character's actions will have a significant impact on the future seasons of the show.

In George R.R. Martin's book "A Dance With Dragons," Jon Snow (Kit Harrington) asked him to borrow some of his few ships to get food and supplies for the Nights' Watch. And in exchange, the bastard son of Ned Stark gave him a guide on how he could reach Stannis so he could collect his debts, International Business Times AU reported.

In addition, in Martin's upcoming book, "The Winds of Winter," Nestoris closed a new deal with Stannis as he acknowledged the Iron Throne's debt and granted him with another loan - a move suggesting the shift of the Bank's Westerosi allegiance from the ruling House Lannister to the then-destitute Stannis, International Business Times AU reported.

Though Gatiss is a new face to "Game of Thrones," Gatiss is popular to many as co-creator, writer, producer and actor of the BBC series "Sherlock," which recently took home three Emmy Awards, including Outstanding Actor in a Miniseries (Benedict Cumberbatch), Outstanding Supporting Actor in a Miniseries (Martin Freeman) and Outstanding Writing for a Miniseries, Movie or Dramatic Special.

"Game of Thrones" Season 5 premieres on HBO in 2015.