Gotterdammerung, Royal Opera House, London <!-- none onestar twostar threestar fourstar fivestar -->

A sensational final instalment

The Royal Opera's new Ring cycle comes full circle, its heroes briefly immortalised in gold like outsized Oscar statuettes, its heroine duly lighting the touch-paper for the eradication of one era and the beginning of another. And as Wagner's "redemption of love" motif finally finds serenity in the strings, there is hope, too, that new beginnings may bring better endings.

Keith Warner's thoughtful, provocative and often thrilling staging has shed clutter and found clarity on its progress to "the twilight of the gods". If there's one criticism that can be justly levelled at the whole enterprise it's that there are simply too many ideas, some clearer and more purposeful than others. Or maybe it just takes time to fully digest them. Since when has any Ring cycle yielded all its secrets on a first viewing? Should it ever?

Let it never be said, though, that Warner does not think big. This Götterdämmerung sets forth like Siegfried's Rhine journey on "new adventures". The mountaineering ropes tell us that there are great heights to be scaled - and unfathomable depths to be plumbed. And as one of Wotan's ravens leads us on, fast-forwarding niftily through our superhero's cinematic voyage of discovery, the expectancy is palpable.

The arrival at Gibichung Hall - a strangely familiar vision of futuristic chic in Stefanos Lazaridis' design - plants the big directorial (and design) coup of the evening. The reflective glass-panelled interior is a chilling replica of the Tarnhelm, the magic helmet which Hagen will use in his plot to murder Siegfried and steal the ring. We are effectively inside the Tarnhelm. We are also very much inside Hagen's head as Warner has him sit through the remainder of the act watching his devilish plot unfold.

Hagen is that great Wotan of yore - the magnificent John Tomlinson. Warner presents him as slick, dapper, bespectacled, and bookish - a dishonest broker. And you genuinely fear he will succeed, such is the way in which Tomlinson uses text like he and he alone owns it. His thuggishly Teutonic vassals don horned crash-helmets as they play rent-a-crowd for the arrival of the hapless Brünnhilde, the reluctant bride-to-be of Gunther, lord of the Gibichungs.

The Royal Opera's music director, Antonio Pappano, was at his dynamic best in this second act. But there was plenty of light and shade in his reading as a whole - mesmerising moments of stasis to counterbalance the irresistible freefall to catastrophe. Orchestral playing really doesn't get a whole lot better than this. How often does one hear such poetic horn playing in Wagner's opera? Only Siegfried's Funeral March failed to convey the enormity of the moment. Or maybe the image of the superhero rising from his death-throes in a determined effort to return the ring to his beloved Brünnhilde simply deflected some of its power. Time will tell.

Time will not, I suspect, do much to heal the vocal wear and tear on John Treleaven's Siegfried. Since last we heard him everything has become such a push that it's stressful just listening. Quite the opposite is true of Lisa Gasteen, playing Brünnhilde, who has blossomed in authority with the cycle and gives the performance of her career in this final instalment. There is some shortness at the top of the voice, but the middle is impressive, and her oneness with the character, her pride, passion, scorn and defiance - not least in the great scene with Mihoko Fujimura's sensationally good Waltraute - is wholeheartedly winning.

You really want her there to see the youth of humankind inherit the earth. A gigantic steel ring rises from the overflowing Rhine, a young girl confidently astride its inner edge. A new beginning. But the same old mistakes? Maybe the unanswered questions are the strength of this Ring.

To 6 May (020-7304 4000)