Imprisoned, two monologues written by Marie Hale and directed by Kasia Różycki and Hugh Allison, are nothing short of astonishing, both in terms of their conceptual basis and the power of their staging.

The first is Something for the Men, starring Meg Lake as Vicky, a middle aged office worker navigating life after divorce. Vicky is both a fully fleshed out character and, to a certain extent at least, a representation of the experience of mid-twentieth century womanhood. This duality, which keeps individual interest while maintaining wider significance, is not easy to pull off, but here it is perfectly pitched. The themes it broaches – and there are many, including domestic violence, the changing place of women in the workplace, social constructions of gender, cycles of bad relationships and internalised repression, to name but a few – are deftly dropped into the characterisation.

As much as the writing is sharp, expressive and insightful, it is really Lake’s masterful performance that makes it such a runaway success. She appears completely at ease on the stage and inhabits her character, right down how she fiddles with pieces of paper or roots in her handbag for a wine gum. She navigates the humorous and serious aspects of the show with aplomb and has the audience totally in her thrall.

The same could be said for the second monologue, Your Sacrament Divine, in which Brig Bennett plays Helen, an accused murderer who is in prison awaiting trial. The second half of the show also tackles big themes; the effects of imprisonment, the legacy of childhood, the role of religion, the genesis of violence and the intersection of the body and medicine. Once again, its great strength is to tether these ideas to a compelling character while still making wider, more universal, observations.

Both actors are alone on stage, but speak to imagined interlocutors. Vicky is addressing a younger colleague, who acts as a foil to her world view and eventually catalyses its collapse. Helen is speaking to a new inmate, but whereas Vicky’s silent listener offers her an alternative way of living, Helen’s monologue is more of a performance, which only rearticulates and reaffirms her way of interacting with the world. The counterpoint here is striking and ties the two acts into a coherent whole.

There are some aspects of the second monologue which feel less polished. There is the occasional stumble, the Glaswegian accent sometimes slips a little, and it feels that the space is not used to its best advantage as some lines are barely audible. But nevertheless Bennett’s instant ease in her character and electric, commanding presence makes her just as captivating as Lake. The way in which disparate subject matter coalesces into thematic unity, as the nature of internal and external imprisonment is probed from various angles, is testament both to the works’ taut writing and captivating performances.

Imprisoned is playing at the Barons Court Theatre until September 4. For more information and tickets, email londontheatre@gmail.com