A man sits inside a glass box. He’s handed himself in to share what he knows about the largest known case of tax fraud uncovered in Germany to date in the twenty-first century. He’s about to be questioned, a process which might take years. Did he realise that what he was doing was illegal, the interviewer asks? It’s complicated, he replies.

The Insider is a spectacular production. The glass box (created by Signe Krogh) is a blank canvas, lit from varied angles to become a bathroom, his boss’ house, a club, a hospital, assorted offices, the park, the interrogation room; and in the midst of this, it becomes a blackboard for an explanation of how the complicated fraud operation came to pass. The entire performance unfolds inside the glass box: a metaphor on all sorts of levels. We listen in on headphones which relay the actor’s voice and a complex binaural pre-recorded soundscape. It has a superbly unsettling effect.

The backstory is well-researched and deftly told by writer Anna Skov Jensen: our young lawyer clawing his way up from the provinces, diligent to a fault, determined to do the right thing, until he meets the man at the top and realises that his version of the right thing was a product of his lack of imagination. Christopher Hvidberg Rønje does a superb job of portraying the well-intentioned lawyer, gradually seduced by his heady reinventing of the rules.

It’s a riveting account of both the history and myriad of contributory factors to this financial scandal (and all the others), not least of which was opportunism, catapulting ‘ordinary’ law-abiding people to the temporary status of quasi-gods. Have you never been tempted to overlook the rules? asks our protagonist, an insidious voice in our heads. We’re left wondering what we would’ve done if sat in that glass box of an office all those years ago.