“Winter is Coming” takes on especially ominous importance when winters in the kingdom of Westeros last more than two Earth years. Based on the epic fantasy series A Song of Ice and Fire by novelist and screenwriter George R. R. Martin, the HBO series plans to tackle one 800-page doorstop novel per season. Game of Thrones is the first of 7 volumes (a 4 currently in print, one being written, two more proposed but not yet published).
There are three principal storylines in the series: the chronicling of a dynastic civil war for control of Westeros between several competing families; the rising threat of the Others who dwell beyond an immense wall of ice that forms Westeros’ northern border; and the journey of Daenerys Targaryen, the exiled daughter of a king who was murdered in another civil war fifteen years previously (War of the Usurper) and now seeks to return to Westeros and claim her rightful throne. As the series progresses, all three storylines become intensely interwoven and dependent on each other. (wiki)