The Wasp starts innocently enough: a cafe, chamomile tea and two women who have lost contact since school. But then cash is slammed on the table along with a shady business proposition, and from there Morgan Lloyd Malcolm’s new two-handed thriller’s disturbing surprises never stop.

Heather (Laura Donnelly) is well-to-do, polite and childless. She arranges to meet with her school tormenter Carla (Myanna Buring), who is pregnant with her fifth child and smoking fags, and from who Heather seemingly couldn’t be more different. But Heather says that their childhood fights are all forgotten. After all, it is twenty years later; Heather is no longer a shy girl with plaits, nor is Carla an aggressive, troubled bully. Instead, Heather need Carla’s help on a tricky problem.

Audience expectations are consistently, repeatedly and rivetingly betrayed by the plot. With the characters’ intentions and actions always shifting, we are perpetually intrigued. Yet The Wasp is not realistic. It is regularly and increasingly devoid of subtlety, absurd to the point of distancing its audience even whilst exciting them. Plot twists hit so constantly that their existence becomes predictable, despite being captivating.

Instead Lloyd Malcolm’s writing excels in the nuances of Heather and Carla’s relationship. Though these women’s stories are extraordinary, their interactions are familiar to us. We know women like these. At times, the naturalism of the dialogue manages to offset the racing, sometimes overblown story. But too often this slow, sizzling tension is abandoned for in-your-face fireworks.

From two characters who could have been plucked off the street comes suitably immersive, relatable humour. The script’s ruthless wit is necessary and appreciated, given its timelessly relevant but dark themes – madness, violence and motherhood, to name a few – and the prickly questions it raises with them. A magnificent cast invests us only further. Buring’s desperate, endearing performance as a mother struggling to provide for her kids is particularly stirring, but Donnelly’s layered portrayal of a haunted woman who acts in control gives a good go at a confusing character.

The Wasp might be crazed, despondent and a terrifying shock of a show, but it is a joyride, never missing a laugh on its speed to destruction, even if it does veer into the absurd. Intelligent lines, a domineering cast and an addictive plot makes this a psychological thriller with a razor sharp sting. At the closing blackout, the audience are giddy with nervous giggles. Oh, that finale.

The Wasp is playing at Trafalgar Studios until 16 January 2016. For more information and tickets, see the ATG Tickets website.