Two children carefully chalk a map on the floor to show us the layout of their school. Each then competes with the other to get the facts correct as they present us with their best, most precise version of what happened on the first day of classes for the year.

It’s no fairytale. They’re recounting a horror story using the language of play.

At Beslan’s School Number One, Chechen terrorists held more than 1200 hostages in appalling conditions for three days in 2004. Teachers, pupils and their families had gathered to celebrate the beginning of the academic year. When Russian security forces eventually stormed the building, more than 300 people were killed; nearly two-thirds of them were children.

This tragic moment in history forms the basis for an imaginative work of theatre — a “child’s gaze” perspective on atrocity.

The performance space at the Festival Centre’s Space Theatre is transformed into a gymnasium under siege using little more than some coat hooks, two bunches of black helium balloons and metres and metres of string.

A girl (Gytha Parmentier) and a boy (Roman Van Houtven) construct this world as they tell us, in a matter-of-fact manner, key facts about their town and what happened to make this is a day that shocked the world. We learn about “them”, the ones who’ve come from beyond the forest, and the reasons they give as justification for their unspeakable violence.

One moment the students are singing to welcome a wonderful new future, the next they are trapped in a sweltering nightmare, arms raised to comply with their captors’ demands.

The children know they must follow the rules. Calculations are checked and rechecked as they ask and answer their own questions. How long has it been since they last went to the toilet? What effect does dehydration have on the human body? What is the ratio of hostages to terrorists?

There is poignancy in the pair’s playfulness and in their unwavering faith in what they believe to be true. Surely an army of fathers will soon be arriving to rescue them? Outside, the mothers wail and the television news crews wait for some footage they can shape to fit their own narrative.

How to comprehend the incomprehensible? How does a child attempt to make sense of an event such as this?

The two exceptional performers use perfectly choreographed physical storytelling (and often humour) to depict the children’s processing of the traumatic episode. As they navigate over and under the string trip-wires they describe what they see, hear and smell, struggling to maintain concentration as first one day, then another and yet another passes with no sign of rescuers.

Writer and director Carly Wijs created Us/Them for BRONKS, a Belgian theatre company for young audiences. The work was a hit at the 2016 Edinburgh Fringe, enjoying five-star reviews during its sell-out season and winning The Scotsman Fringe First Award. Another sell-out season followed in London in 2017.

This is clever theatre, engrossing and powerful. The show is recommended for ages 12 and up and will no doubt open the door for some challenging conversations.

Us/Them is showing at Space Theatre, Adelaide Festival Centre until March 12. Read more InDaily Adelaide Festival stories and reviews here.