Torben Betts’ ‘Invincible’ brings together two couples who couldn’t be more different if they tried, successfully demonstrating the cultural divide between the north and the south in mid-recession Britain.

Boasting a cast of just four – each with their own cleverly-crafted, somewhat stereotyped personalities – and homely yet minimal set design, the actors manage to sustain the plot for its two-hour-plus running time with ease.

The audience first meets Emily, a paranoid, anti-capitalist art-loving, uptight mum who reads Karl Marx, offers her guests olives and is launching an Amnesty International group in the lower class town where she and “posh boy” husband Oliver (Alastair Whatley) – who looks and sounds a lot like Jack Whitehall - have been forced to move to, having lost his job in London.

But when they invite new neighbours Dawn (Elizabeth Boag) and Alan (Graeme Brookes) over for the evening, the differences between their two worlds are glaringly obvious.

Dawn arrives first, wearing very little but with a lot on show, she seems confident but inside she’s hurting and longs for a more fulfilling, “less boring”, life.

Soon after, the star of the show, football-mad postman Alan bounds through the door, having arrived late because England are playing on the telly, with his beer belly showing under a white polo teamed with tracksuit bottoms.

Over the course of a deliberately awkward evening, moments of painful silence and tense facial expressions demonstrate the cultural divide perfectly: the type of language used further exaggerates the division.

Unexpectedly, though, the second act is far darker - tackling serious issues and eliciting a range of emotions from the audience… it’s a real rollercoaster.

‘Invincible’ is at the Cambridge Arts Theatre until Saturday (March 4). For tickets; £18 to £33, visit www.cambridgeartstheatre.com/whats-on/invincible