Diary of a Madman returns to London after an incredibly successful Edinburgh run – ranked amongst the best plays of the Fringe. Entering the Gate Theatre, one passes by its poster on the door, emblazoned with four and five star review ratings. My expectations were high, and the production exceeded them. Because Diary of a Madman is, essentially, perfect.

The play looks to the Scottish Pop Sheeran, played by Liam Brennan. He’s one in a long line of proud painters of the iconic Scottish Forth Rail Bridge. By when the bridge gets put up for sale, their whole lives are threatened. And if that’s not enough an Englishman arrives in town who captivates the Pop’s beloved teenage daughter.

The original Diary of a Madman – a short story by Nikolai Gogol – is described as farcical, but this new narrative, although punctuated with humour and not without its moments of silly delight, treats its protagonist with the utmost respect and compassion. Playwright Al Smith gives his flawed hero dignity: true, Pop will deliver an absurd lecture on how a very unlikely and famous individual’s favourite film is Braveheart (the sort of bluster which had all the audience giggling, as we recognised hearing such similar speeches from our own stubbornly inaccurate friends and family members), but Smith also crafts him an incredibly poignant, beautifully worded confession regarding his relationship with his masculinity. Of course, Smith is a very talented and generous writer, and one feels his sympathy extends to his other characters: three-dimensional persons, with both the potential for great selfishness and incredible generosity. Perhaps Pop’s wife Mavra Sheehan (Deborah Arnott) is a bit of an exception to this – her character is predominately supportive and selfless – but Arnott’s characterisation never rings false, and is always compelling: she must be strong but we see the vulnerability lurking underneath.

This compassion is an incredibly powerful thing, and we are grateful for it. This play is not just about nationality, or class, or the tension between the past and the every-changing present. It is not just a show about madness, despite its name. We recognise the truth and change that is brought about by loss.

The cast are all excellent: Lois Chimimbra, playing Sophie’s friend Mel McCloud, exhibits wonderful comic timing, frequently reducing her audience to stitches, and has the most amazingly expressive eyes. Guy Clark gives a thoughtful, nuanced performance as love interest Matthew White, and is powefully, wickedly sinister as Greyfriars Bobby. Deborah Arnott creates a Mavra who is not only likable, but indeed lovable, and she and Brennan have a great stage chemistry. Louise McMenemy’s Sophie was consistently truthful, whether she was doing the typically innocuous adolescent things that made the audience giggle (showing off to a boy, laughing at a Whatsapp message from someone in the same room as her) or venting the powerful rage that had long been festering within her character. At one point her delivery of a line was so moving it brought tears to my eyes.

Then, of course, there’s Brennan himself, whose attention to detail can be witnessed in the trembling of his hands as he holds a paintbrush out for inspection, and who can deliver the mundane (a little joke about the name of “Matt White”) and the awesome with equal honesty. Every little action he performs seems so natural and correct; every word he delivers is at the right pitch; and he is able both to make the hairs of the back of a spectator’s neck stand up with a brutal line, and consistently demand his or her heart, and total sympathy, throughout the production.

Diary of a Madman, as I said before, is a flawless production about imperfect individuals. It recognises that not all things can be solved by familial tenderness, and that love will not necessarily conquer all: still, it urges us to love, all the same, to consider how we unintentionally (or unavoidable) hurt and help those we love, as they unknowingly hurt and wish to help us in turn – even if the greatness of their own pain makes this latter option nigh on impossible.

Diary of a Madman is playing Gate Theatre until 24 September. For more information and tickets, see gatetheatre.co.uk.

Photo: Via Kate Morley PR