Caravan (Melbourne Festival)

Theatre-mavericks Susie Dee and Nicci Wilks are two of Australia's most fearless artists - playing it safe simply isn't their style. But it's not an avant-garde aesthetic that makes their work so uniquely subversive. Rather, it's the disenfranchised lives they have repeatedly represented on stage: those of Australia's underclasses.

In award-winning playwright Patricia Cornelius's SHIT, directed by Dee and starring Wilks in 2016, they offered an excoriating yet profoundly moving study of the lowest socio-economic pariahs living on the fringes of our affluent society. In Animal, a devised physical theatre work premiered at Theatre Works, also last year, they created a brutally uncompromising view of the entrenched culture of domestic abuse against women that thrives in Australia's poorest communities.

Harrowing as this subject matter is, there is also a surprising undercurrent of larrikin humour and a tenacious, unbroken spirit revealed in their work; the lives of their characters may be bleak, but they are not without wit, ambition and brightly blazing humanity. This is vividly showcased in Wilks and Dee's latest venture, Caravan, a work bringing together four superb Australian playwrights: Angus Cerini, Patricia Cornelius, Wayne Macauley and Melissa Reeves.

Living together in a small, cluttered caravan, bed-ridden mother Judy (Dee) and daughter Donna (Wilks) are bound together by fate, poverty and a complex emotional cocktail of guilt, resentment, responsibility and love. This is a relationship as toxic as it is nurturing; Donna dreams of finding a Tinder date to take her away from this miserable circumstance, while her mother, slowly succumbing to the various ailments a lifetime of drink and drugs has inflicted, does everything she can to ensure Donna remains as both her carer and her only connection to the world outside.

There's plenty of comic irreverence on offer, that springs from a well-intentioned lampooning of the quintessential Aussie bogan, although there's also a strong foundation of sincerity and understanding that stops Caravan from being straight up mockery. Other sequences are geared to shock, including one particularly wincing masturbation scene that toes a fine line between sexual slapstick and gratuitous smut. But beyond this grubby, often crude exterior, beats an emotional heart of undeniable power. Both these women understand that their lives have been blighted by mistakes and poor choices, but that within them is also something valuable, reaching past their rock-bottom social status; in another universe, things may have played out for them very differently.

The nuance and credibility with which Dee and Wilks conjure this mother-daughter dynamic, with its teeming quirks and forensically observed details, is thoroughly entertaining. But with four different storytellers feeding their ideas into this production, there are moments when the plot of Caravan begins to veer dangerously close to soap opera. Ironically, with such a well realised portrayal of these two disposed women underpinning the action, a narrative with such an embarrassment of riches becomes almost entirely superfluous.

Melbourne Festival presents Malthouse Theatre's Caravan, until 22 October.