The warning signs were there. Patrons had received the email warning of graphic scenes of sex and violence. Katie Mitchell herself said at a Friends' Insight evening that “I have a very strong feminist agenda. My focus for this opera is 100% on the female characters.” The message spelled out by the Royal Opera, fearing a repeat of the Guillaume Tell furore, was “Prepare to be shocked!” at this new Lucia di Lammermoor. Those determined to boo the director still pitched up and expressed their displeasure. Although Mitchell's staging is flawed, it did shock... but in a good way.

For much of the production, set in the “Victorian Gothic”, those warnings had seemed like serious overkill. The sex was unsexy and Lucia's murder of Arturo induced audience hilarity when the bridegroom refused to die. Mitchell, in her wisdom, had decided to fill in the gaps in Lucia's story that the audience doesn't usually get to see. Each scene featured a split stage so that Mitchell could pursue her own narrative, the main departure from the plot being that Lucia is made pregnant by her fumbling encounter with Edgardo (conducted at her mother's graveside!). As the wedding celebrations take place, we watch Lucia and her maid, Alisa, murder her unfortunate bridegroom – a bungled stabbing, an attempted asphyxiation and then a knifing in the back finally finishing him off. Would this really send Lucia loopy? Mitchell's masterstroke, however, is to turn Lucia's 'mad scene' into her traumatic response to miscarrying her child in the immediate aftermath of the murder. It is bloody and unsettling and deeply moving. In the final scene, while Edgardo waits to fight his duel with Enrico, we witness Lucia clamber into her bath and slit her wrists.

There are some strong vocal performances. Diana Damrau demonstrated good control in “Regnava nel silenzio” and delivered a mesmeric 'mad scene', movement choreographed to each coloratura flutter. Hers is not the most beautiful soprano – the tone at the top is blanched – and her style in cabalettas was mannered, frequently far too slow, which messed up her phrasing. But Damrau acts the part of Lucia courageously, given the extra demands Mitchell places upon her. Charles Castronovo sang movingly as Edgardo. His tenor is small-scaled for such a large opera house and his upper register is unglamorous, but he delivered a good, honest performance. The vocal standout was Ludovic Tézier's Enrico – his nut-brown baritone has the flexibility for bel canto, but is large enough to project with firmness and menace. Kwangchul Youn was a warm-voiced Raimondo, with a seamless legato, and Taylor Stayton was effective in the minor role of Arturo, the battered bridegroom.

But the singers faced two handicaps. Firstly, although the split stage allowed Mitchell to fulfil her promise to focus on the female characters, this often distracted attention from the (very good) male performances which were taking place. Castronovo had to deliver Edgardo's moving Act III aria to the splashing accompaniment of Lucia running a bath, the taps continuing to run through his own death scene. Somebody call a plumber! The second handicap was Daniel Oren in the pit. From the first row of the Balcony, I had a tremendous view of Oren's conducting. His leaden tempi hamstrung the performance. His baton technique is violent in the extreme, while his stabbing finger cues in singers erratically. He twice sold Tézier down the river with miscues, once in Enrico's duet with Lucia, and again in the Sextet. These singers – and this production – deserve better support from the pit. On the plus side, it was wonderful to have the eerie, ethereal treat of a glass harmonica for the mad scene.

Whether this is Mitchell's Lucia rather than Donizetti's is a moot point, but ultimately – and it takes its time – her deeply psychological production delivers a powerful punch to the pit of the stomach.