How often do you immerse yourself into the world of a play or performance? I mean really immerse yourself, to the point where everything around you, your senses and your entire being are part of the performance? Small Hours at the Hampstead Theatre, directed by Katie Mitchell, performed by Sandy McDade, and written by Lucy Kirkwood and Ed Hime, is theatre of the highest form of immersion and realism that I have experienced.

The keyword here is experienced, for Small Hours sees the audience perched around a living room that has an uncanny reality to it. The walls, ceiling and even carpet beneath your feet (shoes have to be taken off) offer a complete sensory experience. The performance is intimate, 25 audience members along with McDade in an hour-long portrayal of a mother on the brink of post-natal depression and despair. With few spoken words, McDade’s narrative is punctuated or rather dictated, by the baby that screams endlessly in a room elsewhere in this house. Her attempts at watching TV, hoovering and listening to music simultaneously doesn’t stop the crying penetrating the walls.

It is hard not to feel the intensity that explodes from Small Hours. Mitchell’s direction is calculated so perfectly that McDade’s character is real, this room – the walls, doors,  the sofas – are all real (designed by Alex Eales) . Even the household lighting and ring of a telephone where you can hear the person on the other end of the line are all remarkably real. This level of intensity, this realism, makes Small Hours more of a dissection of the everyday human life, through the torment and simplicity of one single mother struggling on her own inside the walls of her home.

It is breathtaking. Climatic, intense – hard to put into words. Is it theatre? Art? Installation? Or life itself? Of course, the situation – a screaming baby, a mother with post-natal depression – allows for it to be a form within the theatre, but it is all so believably real. Even being able to smell the perfume, and see McDade’s character lactating, takes you into a world so finely made that you’d be forgiven for thinking you’d landed in this living room by magic.

Emotionally, Small Hours leaves you quite disturbed. There are dark undertones to the actions of this mother and the silencing of the baby beyond. You’d be hard pushed not to have some kind of reaction to the show, even if it’s wanting to quiet the baby yourself, m/paternal instincts kick into play. Ultimately you’ll be left wanting comfort.

If Hampstead Theatre continues to lead its downstairs space into these realms of experimentation, then I for one can be thankful that theatre can and is being saved from the repeated toss I sometimes witness. Clearly Small Hours has set the bar high for my expectations of realism in theatre.

Small Hours is playing at the Hampstead Theatre Downstairs until 19th February. Information here.