After the king asks him to serve as his advisor, the lord of the North discovers the murder plot of his predecessor as an attempt to cover up the heir’s illegitimate claim to the throne.
A respectable logline for the pilot season.
But I doubt that “Game of Thrones” series was sold on the basis of a logline. It was probably sold on the basis of its source, the series of fantasy novels by George R.R. Martin. The popularity of the series and the video games based upon the series demonstrated the premise had “legs” for becoming a commercially viable series. I doubt that a standard logline was necessary.
I think this is the best plot for the logline.
However, when the series was described to me from friends in 2013, the white walker plot was placed right upfront, as well as the fact that the seasons last about 10 years. I was hooked, but had to ask, ‘wait, there’s kings and queen’s and stuff though, it’s not just villagers running from monsters right?’ I received a ‘yes’ and was really drawn to the fact that the kings and queens didn’t know about the white walkers.