Contractions (Sheffield Crucible)

When Mike Bartlett's Contractions premiered at the Royal Court eight years ago, reviewers routinely used words like "chilling" and "repellent", while acknowledging the humour. This regional premiere at Sheffield Crucible's Studio is not as upsetting as that – until the last 10 minutes (which are chilling), the black humour prevails and laughter and horrified fascination are conjoined.

Much has to do with the performance space. Initially a radio play, Contractions was originally staged in an upstairs meeting room with audiences of 30. The Crucible Studio is hardly spacious, but half a dozen steeply raked rows of seats surround the in-the-round acting area where a simple set of two chairs and a desk very slowly revolves throughout the performance. Rather than part of the action, the audience becomes an extremely well-informed observer, taking in events from all angles.

This greater detachment is by no means a bad thing. After all, many a good play – and Contractions is a very good play – has the capacity to be re-invented in different forms.

Contractions is one of those plays that, by taking little incremental steps from the real and recognisable, makes us believe in the surreal and ultimately inhuman. The Manager (Sara Stewart), icily full of false friendship, interviews the promising young sales person, Emma (Rosa Leslie), about her work and progress and tries to make sure that she has no problems – at least, that's the pretext.

In the early scenes, both find more inflections to "Fine!" and "Good!", some of them faintly menacing, than would seem possible. Then the questions become more intimate, about Emma's relationship with a male employee. The Manager's questioning turns toxic when she marks on her assessment sheet Emma's opinion of the quality of sex with Darren – and then compares it with Darren's view and arrives at a consensus.

The strength of the play lies in the fact that it's impossible to find the point where things that can happen in the workplace are replaced by an absurdist nightmare: the logic is so inexorable and the studied politeness so convincing. And the starting point is real enough: the programme re-prints a 2015 article about whether firms should consider banning workplace relationships.

Lisa Blair's impeccably paced production fully brings out both the blackness and the comedy thanks to two intelligently restrained performances. Never a hair, a phrase or a forced smile out of place, Stewart wisely makes the Manager not an ogre, but a set of company memoranda in a smart suit. Leslie has a wider emotional range to cover and superbly brings out that stage between early acceptance and final outbursts when she is trying desperately to couch her responses in office-think and office-speak.

Contractions runs at Sheffield Crucible Studio until 16 July.