Librettist Thomas Morell modelled the story of the martyrdom of Theodora and Didymus during the reign of the Roman emperor Diocletian on John Foxe’s 16th-century Book of Martyrs, Pierre Corneille’s play Théodore, vierge et martyre, tragédie chrétienne (1646) and Robert Boyle’s novel The Martyrdom of Theodora and Didymus (1687), which aimed to inspire people by ‘rendring Vertue Amiable’. Morell elevated Irene to a prominent voice in the Christian community and portrayed the Roman soldier Septimius’s distaste at cruel orders, his sympathy for the victims and his own conversion to Christianity (not set to music but printed in the oratorio’s wordbook). None of that matters much in Katie Mitchell’s sourly distasteful production, filmed at the Royal Opera House last year. The director provided a caveat that she had updated the action ‘to an alternative modern-day reality where Christians work alongside their Roman oppressors in the Embassy of Valens, the Roman ambassador. Theodora, a Christian and an employee in Valens’ household, secretly plots to destroy the Embassy.’

Even if regarded purely on its own terms, Mitchell’s newly invented plot is incoherent. There is an irreconcilable disjuncture between the characters, motivations and actions we see on stage, and the contradictory music and words they perform. If one mutes the sound, the show functions visually as a violent and lurid thriller about terrorism and revenge. Irene, Theodora and their accomplices (the Messenger takes on the name Marcus) are downtrodden kitchen staff who attempt to make a bomb surreptitiously while surrounded by CIA style security guards who protect the seedy and malevolent Valens (who looks and behaves like a mobster and has a penchant for low-class prostitutes). Didymus is fired from the security team when he objects to Valens’s cruelty, the terrorist plot is foiled by Septimius (who defuses the bomb), Irene is tortured in order to reveal her secrets, Theodora is locked up in a seedy brothel and viciously raped, Didymus dresses up as a lady of the night so that Theodora can escape out of a window (which, it appears, could have been opened very easily all along), Valens arrives for a striptease and guffaws upon recognising Didymus pole-dancing; he puts both Theodora and Didymus into a large industrial freezer next to the kitchen, but Irene and the ‘Christians’ slaughter the guards with kitchen knives and other handily placed utensils. Amid the blood and gore, Irene garottes Septimius and frees Didymus and Theodora, who both go on a killing rampage – Theodora shoots Valens repeatedly, and the chorale-like final chorus accompanies their murderous slow-motion frenzy.

From the musical point of view, the performance is half-decent but not particularly satisfying. Harry Bicket conducts the Opera House orchestra with a fine sense of pacing and style; several numbers are reduced to solo strings, a few middle sections in slow airs are too rushed. Julia Bullock’s Theodora is a compelling and passionate tour de force, even if the characterisations and moods of her music are dictated to by the director’s hamstrung concept. Joyce DiDonato’s Irene dominates the stage for most of the performance; her emotive singing is as compelling as always, but wayward embellishments and cadenzas seldom enhance what Handel wrote. Jakub Józef Orliński looks like Harry Potter playing Clark Kent; his anaemic singing struggles with tuning and English mispronunciation. Gyula Orendt lags behind the orchestra in ‘Racks, gibbets, sword and fire’ but otherwise he is an excellent Valens – conceited, violent yet charming and unable to comprehend why others around him aren’t happy with the way things are. Ed Lyon performs Septimius’s airs with immaculate diction and a shrewd sense of sentences, and his appoggiaturas, precise trills and intelligent embellishments are weighed perfectly. The Royal Opera House Chorus do not aim for shaded phrasing, and their beefy solidity is closer to the Huddersfield Choral Society in the 1950s than Baroque informed contrapuntal singing.