After dragging itself out of the burning embers of Game of Thrones, the highly anticipated prequel House of the Dragon had the potential to veer off in any number of outrageous directions. Its predecessor often seemed to do whatever it felt like. From zombies and sacrificial infanticide to incest and castration, and you could never say it failed to go there. House of the Dragon proved to be more mannered, more sombre and, astonishingly for a cod-medieval series about icy blonds arguing over whose dragon is more fiery, more subtle. And here it is now, this enormous, splashy spin-off of one of the biggest shows of all time, once again insisting on being so frustratingly subtle about everything.

In the past, this subtlety was a strength as well as a weakness, and that remains the case for the first four episodes of season two, which is all that HBO released to critics in advance. It means that the characters have more depth, it is sparing with the default crude shocks, and it worms its way into your mind with a deceptive gentleness. Again, given that the beheadings and hangings and fights to the death arrive fairly promptly in season two, I appreciate that gentleness is another unlikely virtue. But it is there, nonetheless. This makes for a moreish series that is engrossing almost by stealth. By the end of episode four, when the excitement arrives in earnest, it certainly feels as if it has earned the right to show off.

However, it makes you work for it before you arrive at that point. This time, instead of opting for the ambition of a 20-year timeframe, it focuses on the doom-laden present, in which two queens, former close friends and stepmother/stepdaughter Alicent (Olivia Cooke) and Rhaenyra (Emma D’Arcy) and their houses are on the verge of war. It would take several pages to fully recap the intricacies of family relations here, but Alicent is the mother of the new King Aegon, who is Rhaenyra’s half-brother, and whom Rhaenyra and her supporters view as a usurper. Between the Blacks and the Greens, conflict is imminent, owing to a combination of medieval sexism, bloodthirsty advisers and the confusion over a dying man’s last words.

The opening episode follows the pattern set by season one, in that its characters spend most of the time talking about what is going on in Westeros. This is handy, as the cast is enormous, they’re all loosely related (by blood, marriage, or both) and their names are dense with similar-sounding vowel combinations. Filling the episode with council meetings, diplomacy and clandestine chats in the shadows allows it to serve as an extended recap. This would be lazy for most shows, but ends up being useful in this case. In isolation, I cannot imagine this is the sort of all-guns-blazing opener that will win over new fans, and it may only sate the old ones.

The initial impression is that, once again, this is going to be Game of Thrones without the fun. It plods along, glumly emphasising the fact that war is bad, that the pursuit of vengeance leads to more gratuitous deaths, and that with weapons as mighty as dragons on each side, the only outcome is mutually assured destruction, which certainly is a parable for the renewed nuclear panic of the present. Game of Thrones could be funny, but House of the Dragon seems deathly afraid of humour. Worse, it looks as if it might be on the verge of wasting its best characters, sidelining them for yet more meetings in which simmering looks and loaded barbs do the heavy lifting. Rhaenyra and Alicent are both in a state of deep grief, and hover around the peripheries of the action. D’Arcy and Cooke are excellent scene partners, but they are separated by the story for far too long. Even Matt Smith, as the dastardly uncle/husband Daemon, is taken out of the ensemble and sent off to do his own thing.

Yet, as soon as the first episode has skulked away, I begin episode two, and not too long after that, I curse HBO for not releasing the entire season at once, which suggests that it might be worth being patient with it, flaws and all. This slow opener starts to build up the story with steady, elegant layers, allowing it to weave its melancholy magic. I still think it is strange that a show about dragons should be so bashful, but somehow, despite this stubborn tendency to talk everything through, House of the Dragon once more becomes unmissable and thrilling television. Eventually.

• House of the Dragon aired on Sky Atlantic and is on Now in the UK; in the US it airs on HBO; in Australia it airs on Binge.

Source: theguardian.com