HBO Accidentally Drops Massive 'Game Of Thrones' Spoiler

Warning: This post contains spoilers (it's in the headline, guys), but you can blame HBO for the big one.

Dedicated fans of the US cable channel's global smash, and Australia's favourite show to pirate, Game of Thrones are covering their eyes and ears today – well, those who still can are, at any rate, and it's all the fault of an official episode synopsis.

It's a little piece of writing, but the impact could be huge.

Seriously, this is your last chance to get out before we open the spoiler can. Consider yourselves fairly warned.

The synopsis for the fourth episode of season four, Oathkeeper, which aired on Sunday (April 27) in the States, accidentally revealed the identity of a character that – while mentioned – hasn't even physically appeared in George R. R. Martin's lengthy tomes that make up the A Song of Ice and Fire series, the books on which GoT is based.

Pic: Reddit

As you see above, the write-up (which has since been changed) originally pointed to the appearance of a character called the Night's King, which wouldn't be a big deal if the Night's King had appeared in the books in any capacity other than “folk tale to give children nightmares”.

Yet, in Oathkeeper, there he apparently is, in all his pasty, horned, infant-killing, unmistakably king-of-the-White-Walkers glory.

Viewers who have also read the books will recognise further implications of the leak, in that the identity of the Night's King – a former commander of abstinent northern guardians the Night's Watch – is widely speculated to be tied closely to one of the series' primary dynasties. The ones obsessed with winter. You know the ones.

What this means for the show is that, in some respects at least, the writers are beginning to introduce elements into the plot that Martin hasn't even written about yet – not without the author's blessing or guidance, mind you – but it will be hard to fairly judge the choices the TV show makes until the rotund suspenders-loving wordsmith catches up on that front.

It's an unfortunate thing to happen to HBO, for whom Game of Thrones has been a double-edged sword this season. The world rejoiced at the snuffing out of the adolescent psychopath that was King Joffrey (Jack Gleeson), and with equal fervour muttered in confusion and anger at the show's decision – and consequent defence thereof – to turn what was originally a consensual (albeit still disturbing) sexual encounter between siblings Jaime (Nikolaj Coster-Waldau) and Cersei Lannister (Lena Headey) into straight-up rape.

Still, it's not the first time a cable channel has inadvertently jumped the gun on its own content. In 2012, fellow drama heavyweight AMC let slip on a promo DVD the then-impending death of Shane Walsh (Jon Bernthal) – at the time, one of the primary characters on post-apocalyptic zombie saga The Walking Dead.

... Why does it always have to be zombies?