'Game of Thrones' fans in Madrid were treated to some never-before-seen behind-the-scenes footage special exhibit set up by HBO Spain and it tease a Targaryen-Lannister showdown that we can't wait for.

In the teaser, fans were shown Daenerys' army of Unsullied, including Grey Worm, taking on a Lannister army in an undefined location and while it could just be any Lannister stronghold throughout the Seven Kingdoms (including the recently won Riverrun), many think that it is in fact Casterly Rock, the never-before-seen ancestral seat and home of House Lannister.

This would be a bold move by Team Targaryen but seeing as Tyrion Lannister is now Hand of the Queen, it makes sense that his intimate knowledge of the Casterly Rock would be used to gain the upper hand against his sister while she rules in King's Landing, effectively isolating her there and holding their home and land to ransom.

But what that means for their brother Jaime, who is seen fighting at the battle, is anyone's guess.

The footage also holds glimpses of an unidentified maester in the Citadel library, a fierce battle at sea at night (Euron Greyjoy finally making all that trouble he promised?) and Brienne and Podrick training hard.

'Game of Thrones' returns on Monday July 16th and will be simulcast on Sky Atlantic at 2am before being repeated again at 9pm that night.