Do you remember a time when you realised that the people or systems that you’re told are supposed to protect you proved themselves to be at best inadequate and at worst destructive? As a society we tend to underestimate children in the face of persevering their innocence; why is that we react with such fear or shock when a child swears or shows a knowledge or understanding of something that we thought beyond them? We often talk of young people who are forced to grow up too quickly or act like ‘mini adults’; it’s something I take umbrage with when it’s attributed to me. Children are remarkably adept at adjusting to their circumstances which often means mimicking adult behaviour or perpetuating systems that they think are stable only for them to disintegrate. Polly Stenham’s play Tusk Tusk shows three children who have been left behind by their mother and their attempts to keep it together until she returns. Neglect and abandonment have been consistent in Claire’s upbringing of her three children Eliot (16), Maggie (14) and Finn (7). She’s severely mentally ill and it is alluded that she suffers from psychosis, mania and suicidality. Whilst you get the impression she’s doing her best she sometimes disappears leaving her children to fend for themselves.

Eliot turns into a game with himself as the ringleader, Maggie is a pragmatist with the clearest insight into the direness of their situation and Finn is trying to protect his siblings as much a they are him. Even though Claire never appears she is a chilling presence throughout the piece; you can feel her in the coping mechanisms that the three have developed, in the words they parrot, the fierceness with which they love, protect and ultimately let each other down.

Patalog theatre’s production is presented with such nourishing intensity that you don’t so much watch as bear witness. Ruby Rees directs with startling empathy and emotional precision. It is a credit to her microscopic attention to detail that I frequently pondered who was to credit for the ingenuity of the staging, her or Stenham. There is something sacred in the ways she has curated a space for her collaborators to safely explore raw and painful emotions, especially when one of the actor’s is ten years old. It can be a viscerally painful play to watch but every moment feels fully earned due to the truth and integrity of her vision.

Much of the sublime pain that comes from this piece how intimate and lived in the three central characters are portrayed. Stenham has a remarkably keen ear for internalised sibling dynamics and speech; they are bright, funny kids but never come across as precocious mini adults. The dialogue is at times incredibly funny; with smart, realistic gallows humour and occasional moments of breathtaking poetry. At this performance the role of Finn was played by Sol Feldman who shares the role with Liam Smith. He’s a gentle, loveable presence who inhabits his role completely; some of the best moments of levity come from his warmth and playfulness. It’s a credit to Rees and his co stars that he is so natural at taking in and processing the events around him. Ben Walter plays Eliot’s wounded grandiosity with spectacular resonance; watching the emotional and physical layers drop from this charismatic young man to reveal a self destructive mania and a scared, frightened and betrayed little boy is paced with gut wrenching accuracy. Markella Kavenagh’s physical and emotional commitment to Maggie is revelatory; she is a stunningly written and performed character. She has a bitterly hard-won world weariness and stoicism and the writing takes her to some immense emotional extremes. It’s one of the bravest and intelligent performances I have ever witnessed and one which will be seared in my memory for a very long time. It can’t be overestimated how seamlessly these three performers have committed to the emotional realism of their characters situation. All are exhausted, mal nourished and traumatised. The imagination and insight with which they influence the characters are a triumph of writing, direction and performance. The chemistry they share is seamless, the family unit they have developed is fiercely committed, co dependant and irrevocably fractured but you can see how unbearable it would be if anyone was to come and break their bond.

But the outside world must enter at some point; Stenham skilfully creates rich and nuanced characterisations for her ancillary characters. Lucy Ansell is stupendous as Cassie, who shares an uneasy romantic chemistry with Eliot. She is a gifted physical performer, she must play her first volatile scene highly intoxicated, a challenge that she fully commits to with humour and pathos. Cassie is a fascinating balance for Eliot; she too has grown up tough and also developed a resilience and resourcefulness that is very different to his. Jayne Louise O’Connell and Glenn Van Oosterom enter as family friends Katie and Roland towards the end of the play to lead it to the final denouement. They are both comedically upper class and oblivious but in the briefest of moments evoke an entire history and dynamic. Mr. Van Osterom is suitably pathetic, and Ms. O’Connell strikes a superb balance between bourgeois condescension and fierce empathy. It would be unfair to reveal the extent of their functions without spoiling key plot points but there are moments in Ms O’Connell’s performance that contain a heroic tenderness that stand amongst the most moving in the play. Sean Rees-Wemyss has done a brilliant job at coaching them through the dialect and accents with impressive emphasis on class and region. Joshua Bell is also responsible for some effortless stage combat that sits in the actor’s bodies and capabilities; from my place in the audience it looked thrillingly naturalistic.

Lighting and Sound design by Richard Vabre and Finnian Langham is appropriately evocative without ever detracting from the action on stage. It’s an admirable skill being able to produce good work without drawing attention to yourself.

Tusk Tusk is one of the most open hearted, loving and truthful pieces of theatre I have seen in a while. The artists currently occupying St Martins theatre are some of the most ingeniously courageous ensembles you’re likely to encounter this year. It’s not an easy play to witness but it is worthy.