ESPIONAGE, double, triple and possibly quadruple agents, and quantum physics are the stuff of Tom Stoppard’s play, Hapgood.

It’s a clever play, but was critically panned on its West End debut. It’s easy to understand why many found it hard to follow, with its spy-talk, theorising about physics and lightning-fast plot twists.

However, Southend-based Full Circle’s production at the Dixon Studio Theatre lends the play a slick feel, while some engaging performances make it well worth a look.

Ostensibly, it’s the story of Hapgood, an MI5 intelligence boss and single mother and the problems she faces when a meeting goes wrong.

Her boss suspects Kerner, a brilliant Russian physicist whom Hapgood trusts, while her CIA counterpart suspects Hapgood herself. So begins a complex game, as she sets about unmasking the mole.

Duality in science and human nature is key to the mystery. There are twins, both real and imaginary in the KGB and in the UK, and Kerner explores the ideas of electrons being able to be in two places at once.

Meanwhile, Hapgood is torn between her dual roles as mother to an 11-year-old son and ruthless intelligence boss.

Kate Austen, in the central role of Hapgood, is strong throughout, giving an emotional performance. She is at her most believable in the roles of mother and lover, though she also shines when playing Hapgood’s elusive twin sister.

She’s so good at this, the audience is truly left wondering who she really is.

Jeremy Battersby, playing her boss Blair, is a real treat – a gentleman spy straight out of a John le Carre novel with the demeanour of a classics professor. He is constantly frustrated at the scientific theories put forward by Kerner, movingly played by the excellent Neil Patrick.

The simple setting of the Dixon suits this contained, elegant piece, but a little more attention to costume detail would have gone a long way. I found myself distracted by modern brands and incoherent design which made it hard to work out exactly when the piece was supposed to be set.

However, there are strong performances and this is a sharp, clever thriller – very enjoyable as long as you don’t worry too much of the quantum physics.

Dixon Studio, Palace Theatre
London Road, Westcliff.
£12. Nightly 7.45 until Saturday, plus 3pm matinee, Saturday,
 01702 351135