You could read the books. You could borrow your friend's Sky Go account to watch the show. You can spoil yourself by just existing on the internet. Or you can catch up with the last season of Game of Thrones through this surprisingly good recap. It covers the big happenings of Season 3—who boned, who died, who's alive—all through the medium of emojis.
To be fair, you need to sort of know who's who (or at least, who's what animal) in order to follow the emoji recap, made by Cara Rose DeFabio, but if you do know a bit, it's pretty damn funny how it illustrates what happens