If Micheal Billington had reviewed 'My mate nearly died!' at the National Theatre, a parody.

'Who owns our theatre and who think they have a right to it' Susanna Clapp almost says in the other Guardian review of the recent NT play Common. In this dramatic modern exploration of the true meaning of ownership, it's the National Theatre who have pushed the boat out in terms of ambition and indeed definition of "theatre" and one would argue, it's close to the edge of the waterfall. Yet for all its flaws, it has a dark, imaginative power that, I suspect, make it stick in the memory.

First you have to understand the play's background: the practice of locking up large spaces and employing security to oversee the largest factory in south London that houses myriad departments all operating on their own hours has been going on for decades, with the Royal National Theatre reaching its permanent home in the late 1970's thanks to a lot of money and Churchill's daughter. 

The subject is also explored in Law's earlier online work, where he and his comrades expose the security flaws of other large establishments, but here, Law is not really concerned with his back catalogue but more with the challenge of jumping walls, climbing balconies and getting people to comment on his Instagram picture in order to win a GoPro. Yet this is one of the first publicly-owned buildings that Law explores, and, as such, we are presented with the powerful question of whether or not we, the audience, know the trick about wearing the high-vis jacket? He uses it as a symbol for a theatre industry in turmoil, with outreach budgets slashed, how are new audiences expected to get access to the wonder of the backstage?

Into this hallowed building steps the figure of Law, he plays principal antagonist and half of the security department's problem. It is fascinating that he is played with unbreakable overconfidence by newcomer to theatre Ally Law who,  according to his near 300k Youtube subscribers, is an iconic hero. Having played 'man trespassing in other buildings', Law is soon to find this new role and building is well within his grasp. 

Law is unwavering in his performance in a work I am tempted to call cocky. He explores the deserted theatre, takes in the rooftop view then proceeds to climb the Olivier fly tower's balconies and even sleeps on a rolled up stage curtain. Is this a commentary about the state of security of our National Theatre? Is this a piece exploring the raw human thrill of risking one's life to walk along a suspended lighting truss and draw a cock and balls in dust on a bar? Is this a modern filmic interpretation of the mass trespass of Kinder Scout, where instead of boots on the ground we have views on the Youtube, and instead of public land it is our public theatres?

Ally Law sees the backstage world for the first time.

It is a mixture of none of these and more. Law, with his brown knitted jumper cuts an unusual figure of midnight prankster and socialist commentator. His partner in not-that-much-of-a crime is excellent in scaling balconies and walls and nearly getting himself killed, and in the highlight of the second act, performs some of the most avant-guard choreography ever seen on the Olivier stage. 

The pace, however, is challenging. One minute Law seems to be disregarding the sanctity of an actors costume by putting it on himself, the next he is atop the highest roof in the building planning to return for new years, a plot point that considering his notoriety and blazingly obvious identifiable qualities is optimistic to the point of stupidity. He is also blessed with the capacity to rise from the dead. The moment involving the security guard is so knife edge, it was a shame there was no one in the audience to appreciate the palpable tension in the room.

Law also makes things tricky for the audience by fashioning dialogue full of swear words and colloquial language. It is this improvised script that really shows the lack of a coherent narrative, almost certainly a by-product of the devised nature of the show, a style apparently popular in France.

As we know, this is not Law's first foray into online theatre.  In 'we almost escaped from the police!' Law takes us into the mind of someone who sneaks into swimming pools after dark; in 'Sneaking into london zoo *busted*' we are brought face to face with the morality of caging wild animals for the financial gain of humans; and in 'These security guards were dicks!' he brings us a physical manifestation of the struggle of authority over freedom of movement. But here he is working on a much bigger canvas, that of the Olivier stage to create a radical environment that shows us the theatre at a pivotal moment in our nation's artistic history.

And yet, and yet, when one has listed all of the production's problems, there is no doubt that Law has created something unique and strange, and hugely extended the online audience reach of the National Theatre. One might even go as far to say an audience very unlikely to attend in person before.

You will see many more tidy, well-organised productions than this. But Law's unique take on the appropriation of public theatres and his reaction when he first steps into the backstage world transcend its faults. His production is often baffling, but it eats into one's own consciousness and makes one nervously excited about where he'll go next.