Debussy’s Pelléas et Mélisande is a work of half-lights, of thoughts left hanging, questions elliptically answered. Performing it in a theatre that lets in the full glare of the midsummer sun is a challenge that director Michael Boyd and his designer Tom Piper have taken head on in their new staging for Garsington Opera. Their static, single set is a gloomy, once-glamorous interior in a state of severe decay – the rather unlikely design inspiration came from Detroit’s abandoned art deco theatres – with moss growing on the walls and plaster hanging off the ceiling.

Within is contained every scenic necessity for Debussy and Maeterlinck’s story: the well (a flooded hole in the floor), a balcony for the ‘Rapunzel’ scene with Mélisande’s hair, a perilous broken stairway for Golaud and Pelléas’ journey into the castle vaults and an abandoned corner under the stairs that does duty for the beggars’ cave. The set and its grubby hues thus shield the action from much of the Garsington theatre’s natural light, but Malcolm Rippeth’s effective lighting has its own part to play, ironically when the opera’s brightest scenes – the dazzling sunlight after the scene in the vaults and the golden sunset that illuminates Mélisande’s last breaths – happen once the real sun has long set below Wormsley’s treeline.

But a theatrical production is more than merely its set dressing. Boyd, former artistic director of the Royal Shakespeare Company and here directing only his third opera after last year’s Garsington Onegin and a Royal Opera Orfeo, pursues what one might term an enhanced naturalistic approach. There’s something about his direction of the main characters that means that their full human capacity and interaction doesn’t really tell until the second half of the evening. In one sense that’s how Maeterlinck plays things, poking at the truths without really revealing them – what are we supposed to make of Mélisande’s unstated past, for instance, when she’s found at the very beginning in a bedraggled wedding dress and having lost her crown?

But there was a certain distancing effect here, perhaps as a result of the characters not initially emerging from behind the starched collars or glamorous gowns of Allemonde’s hermetically sealed court. For this is an intriguing irony of a family, dressed to the nines in an utter ruin of a ‘castle’ while sealed off from an outside world which, we are briefly told, is in famine. Some of the more interesting character direction is reserved for ‘petit’ Yniold, Golaud’s son, who here has an almost Puck-like omni-presence and if not marshalling events at least becomes more a part of them than we sometimes see – and moreover, to extend the Midsummer Night’s Dream allusion, his use of his illuminated ball to represent the moon has shades of Pyramus and Thisbe. The one visual sour note was the way the murdered Pelléas was left to pick himself up and slink off stage at the start of the final scene.

American soprano Andrea Carroll, now a member of the Vienna State Opera ensemble, played Mélisande with a fascinating combination of innocence and subversiveness, less a waif than a latent femme fatale, and her bright, open sound cut through the visual gloom. Jonathan McGovern’s youthful Pelléas still needs to free itself a little from the printed page of the score, as it were, to use the words and music more as a natural extension of the voice, but there was an attractively ardent quality about his performance as a whole.

We were treated to a highly successful double-act as Golaud: the scheduled singer, Paul Gay, was suffering from a throat infection, and mimed the role with dramatic intensity, while Garsington’s understudy system came to the rescue in the form of recent Guildhall graduate Joseph Padfield, who gave a most impressively mature vocal account of the part from the side of the stage – and won himself the biggest roar of approval during the ‘curtain’ calls. Brian Bannatyne-Scott brought nobility to the role of Arkel – his monologue in the final scene highly moving – and Susan Bickley was an imposing Geneviève. Treble William Davies sang the difficult role of Yniold with élan and apparent ease, and Dingle Yandell (Doctor) and William Thomas (Shepherd) completed an accomplished cast.

Beginning a new five-year association Garsington and allowing the company to increase the number of operas presented each summer, the Philharmonia Orchestra produced a luxuriant and multi-layered sound, and if conductor Jac van Steen’s tempi were sometimes on the languorous side, there was always the sense of forward impetus and of the music driving the story.