Adura Onashile’s new play Expensive Shit rises to its title, travelling between the bogs of a grimy modern-day Glasgow nightclub and The Shrine club in 1970s Lagos. Peering into Karen Tennent’s skeletal bathroom set, the audience are privy to the preening and drunken revelations of the women who pass through. The play’s time-hopping allows Onashile to explore how little things have changed, in spite of the intervening time and geography: in Glasgow, men pay to look at women via one-way bathroom mirrors; in 70’s Lagos, women prostitute themselves to club-goers in the hope of a brighter future. The men may be anonymous and absent in this four-hander, but Onashile shows the dreadful abuse they can inflict on vulnerable women and how a culture of deception and complicity helps them get away with it.

Uniting the disparate time periods is Tolu, a steely but ultimately sympathetic Sabina Cameron. In the Shrine, the club of legendary musician Fela Kuti, she coordinates the work of a group of dancers including the vivacious Diana Yekinni and Jamie Marie Leary. Rehearsing their beatific routines to Africa ‘70 night after night, they are buoyed by the hope of a place in Kuti’s band; the reality, unsurprisingly, is far less rosy. Decades later and Tolu is a toilet attendant in Glasgow, ‘queen of the shitter’ as she calls it, earning tuppence by flogging toiletries and beauty products to women on the pull. If times haven’t changed, then Tolu has: in the 70s, she refused to beggar herself for male onlookers; now, she’s complicit in a seedy scheme with the men who lurk behind the mirrors, betraying the trust of the women who come into her bathroom in order to make a living.

Onashile’s writing seethes with rage, but it also feels underdeveloped, dealing a soft blow where it could be hard-hitting. Frequent dance routines paper over the play’s insubstantial plotting, with far too much left unsaid: in both the 70s and modern day sequences, the girls’ lives outside the swinging toilet doors are only sketchily drawn, while vital information as to the historical context of Kalakuta are left to a piddling paper handout as you enter the auditorium. It makes the writing un-involving, at times even uninteresting. There are fine performances from Cameron, who navigates Tolu’s transition from defiant pariah to embittered victim, and Teri Ann Bobb Baxter who falls prey to Tolu’s devastating scheme, but they are done a disservice by a play that doesn’t feel ready for the stage.

Expensive Shit is playing at the Traverse Theatre until August 28.