We all know what happened on April 20, 1999 in a seemingly normal American High School. It was a tragedy that shook the entire world and anyone over the age of 21 will remember seeing the sickening pictures and news reports that inundated the media. Dylan Klebold and Eric Harris, two students at Columbine High School, shot and killed 12 students and a teacher before turning the guns on themselves. All the world could do was ask 'Why?'. 'Columbinus' is a beautifully written, honest look at the events of April 20th and those that led up to it. Beginning with a huge soundscape of voices chanting, almost rapping, their morning routines, it never really lets up on your senses from there. You are invited into the private lives of seven adolescents at Columbine; Loner, Freak, Perfect, Faith, Rebel, Geek, Jock, and they show you everything, every weakness. It's hard to believe the people on stage are still at school themselves. They handle the, quite honestly horrific, material tenderly and without parody, with a maturity that seems well beyond their years. Hailing from Gordonstoun School, this group are the first English company ever to perform 'Columbinus' and, my word, do they do it justice.The staging is simple and yet phenomenally versatile, seven school desks, seven chairs. The company stack them, rearrange them, climb on them, with a slick ease born, I'm sure, from dogged rehearsals and ensuring that it's never boring to watch despite it's simplicity. The screen at the back depicts poignant photographs of Columbine itself, helping to set the scene of being in a certain class. But the masterstroke for me, and one which made every audience member shuffle uncomfortably in their seats, was the video camera. We see on stage two boys talking to the camera about the 'Judgement' they are planning and their every move is shown on the big screen above them for the audience to see. It's like watching the actual home movies made by Klebold and Harris and it's terrifying. When we finally reach the Library, you're already on edge. And then they start detailing the nauseating events that happened there. It's handled tastefully and it's heart-breaking to watch. They slam desk lids to depict gunfire, which is scarily effective and left me wincing with discomfort.The standard of performance here is astonishing. These kids can't be more than 18 and yet, here they are, depicting something so horrendous with such honesty that, I for one, left in shocked tears. The seven-strong ensemble support each other and work together as a unit, with a cohesion which can only be described as exceptional for a group so young. There are stand out performances, of course; the two boys playing Klebold and Harris (Alex Macphail and Peter Jenkin) are utterly convincing and petrifying. Macphail as Klebold had stage presence that was so outstanding that I could barely take my eyes from him. In the scene in which we see him pointing a gun at a quivering girl in absolute silence, for what seems like an age, the intensity in him radiated through the audience with such force that more than one person simply had to look away to control their emotions. Other notable mentions must go to Hannah Adams (Faith) and Dan Lloyd (Geek) for wonderful control of their characters and believability that went beyond saying a few words in an American accent.Therein lies the only complaint I have about this stunning production. There were times where accents wavered slightly and sentences were lost due to under-articulation but it never detracted from how involved I had become in the narrative. It just became frustrating that it was so close to perfect and yet, through one tiny detail, lost a lot of authenticity. Dealing with Columbine is difficult at any time; immersing yourself in it as this young cast have is tantamount to bravery. Go and see it before you leave Edinburgh. This is one of those shows that just cannot be ignored and when produced by such a talented young group I don't know how it could be. I have a lot of respect for them for undertaking such a mammoth task and creating a moving, sensitive tribute to those affected by that day. I defy you to hear those desks slam without flinching and leave without some form of lump in your throat.