Melissa Blease reviews Christmas Eve on at Ustinov Studio, Bath, until Saturday 18 November

The Ustinov has sprung back into life for autumn, opening a new season with yet another dream team production. The latest work from acclaimed German writer Daniel Kehlmann, Christmas Eve stars Niamh Cusack and Patrick Baladi, and reunites Ustinov Artistic Director Laurence Boswell with translator Christopher Hampton, who adapted both Florian Zeller’s The Father and Kehlmann’s The Mentor in previous collaborations with Boswell in Bath.

Christmas Eve is billed as a 75-minute thriller, played out in real time, and involving only two characters. But this is not a Hitchcockian/Christie-style suspense drama, nor does it rely on startling special effects, tension-inducing lighting or nerve-jangling music to bring the scenario to life.

It relies instead on the heady combination of a great script and a perceptive, virtuoso director who understands just how powerful a simple set, two exquisite actors and slickly intelligent dialogue can be.

It’s almost midnight on Christmas eve – the one time of the year when most of us attempt to hang up our hang-ups next to the kids’ stockings, put our cynicism on hold and adjourn all manner of angst for at least 24 hours. But as we all really know, the notion of peace prevailing on Earth – even for just one day – is as fanciful as the idea of a visit from Santa. In real life, the folk who deal with the threat of terrorist attacks don’t get a day off for Christmas… and neither do the terrorists who have plans in the pipeline.

But is philosophy professor Judith a terrorist, or just another bleeding-heart middle-class armchair radical preaching her old-fashioned left-wing clichés about how democracy has failed society to the converted? Thomas – the interrogator who has had Judith bundled out of a taxi on the way to her parent’s house and into a bleak interrogation room – thinks she’s the former, and believes her to be more active anarchist than abstract academic. Or does he?

Either way, Thomas doesn’t have long to find out whether his instincts are right are wrong, but he’s armed with intelligence that could incriminate Judith, including evidence – albeit flimsy evidence – suggesting that she may have plans to claim responsibility for a bomb set to go off at midnight.

Cusack is fascinatingly charismatic as Judith – even when her apparently impassive, detached demeanour fleetingly gives way under Thomas’s unrelenting provocation she remains stoic and demure. And Baladi is the perfect foil: good cop/bad cop rolled into one, partly contemptuous of Judith’s ideological rhetoric, but partly fascinated, too. As the relationship between the two is forged in real time, we’re involved in the cat-and-mouse wordplay as it happens. At times it’s like being caught between two ideologically-opposed friends at a dinner party, wishing we could move the conversation on from discussions around the rights of the individual to protest, the rights of the police to act on intelligence – by whatever means they glean it – and the rights of innocent bystanders not to be blown limb from limb, and on to more lighthearted matters.

But as is also typical in such situations, we find ourselves sympathetic to each antagonist in turn as they make their case, often inwardly acquiescing to viewpoints we’d secretly rather not admit to holding. Meanwhile, the clock ticks on, and midnight is fast approaching. Questions must be answered, resolutions must be made, action must be taken.

This particular Christmas Eve could hardly be described as a have yourself a merry little yo-ho-ho, jingle-all-the-way affair. It is, however, a subtly powerful, deftly affecting new drama that lingers in the consciousness long after the clock stops ticking.

Visit: theatreroyal.org.uk/Ustinov-Studio

Main image: Simon Annand