House of the Dragon kicked off one of the saddest storylines in Game of Thrones history

*Warning: Contains spoilers for House of the Dragon*

If the show stays true to the books then House of the Dragon has just got the ball rolling on one of the saddest storylines in the history of Game of Thrones.

Last week it was Paddy Considine's stellar performance of the final days of King Viserys that brought audiences to tears, now it looks like House of the Dragon is lining up even more emotional moments.

By now fans of the show and Game of Thrones will be well aware that the world of Westeros is a pretty miserable place to live and there's not many happy endings.

With that in mind, last night's episode introduced us to Erryk and Arryk Cargyll, twin brothers who serve in the Kingsguard and are sworn to protect whoever sits on the Iron Throne.

Played by real life twins Elliott and Luke Tittensor, they've been in the background of episodes before, but in fresh episode 'The Green Council' we got a proper introduction to the knightly brothers.

Tasked with searching for Targaryen prince Aegon, who has gone missing in the aftermath of his father's death, the brothers set out on a search that changes their fate forever.

Given how terrible Aegon (Tom Glynn-Carney) is, the only happy ending to this story would have been if they'd never found him at all, but sadly the prince – who definitely wasn't promised – did eventually turn up.

Twitter/@BethElderkin

However, Erryk's search brought him face-to-face with the brewing corruption and power plays at work in the Red Keep, and he didn't like what he saw.

While the Kingsguard are meant to be loyal to their King, the big question House of the Dragon seems to be building up to is who is going to sit on the Iron Throne.

Viserys made it pretty clear that daughter Rhaenyra (Emma D'Arcy) was his chosen heir, but in his final moments Queen Alicent (Olivia Cooke) mistook his last words as endorsement of their eldest son Aegon.

Alicent then decides to push forward with putting Aegon on the Iron Throne, which is probably one of the worst decisions of all time.

With Westeros split and proclaiming different Targaryens as the rightful heir to Viserys, an absolutely massive civil war is brewing between the Greens and Blacks.

It's only a matter of time before things spill into all out conflict and the twins sadly end up on different sides – it's literally brother against brother.

Twitter/@targaryen_the

In George R.R. Martin's books the brothers come to a sad end as they face each other in battle and end up killing one another, dying together in a war

Still, it could be quite a while before we get to see the full extent of this storyline play out, as Game of Thrones author George R.R. Martin reckons House of the Dragon will need four seasons to tell the whole story.

That's great news for fans of the show as it's more of what they love, but it gives the showrunners the chance to really drag out the tragedy of the plotlines.

UK viewers can catch House of the Dragon on Sky Atlantic and NOW, while the show will be be available in the US on HBO and HBO Max. Aussie viewers can catch it on Mondays on Binge.