‘What’s your topline?” It’s perhaps one of the most frequently heard questions in the newsroom. When an editor asks, a reporter is expected to have a convincing answer. It’s easy to overthink, but can be hard to get right. What, in one short and compelling sentence, is your story about? As a reporter on the Guardian’s investigations desk, I often work on stories where it can take a few attempts to hammer into shape a concise and intelligible topline. When the facts of a story are complex and contested, it can take time and careful wording to come into focus. The question has been on my mind recently as my first play, The Inquiry, prepares to open at Chichester Festival theatre. When asked what the play is about, my response still feels hard to pin down. Among the many differences between playwriting and reporting I’ve encountered, constructing a convincing answer to this essential and routine question for a journalist is a more demanding task for a dramatist. In short, I explain, the play is about a public inquiry. It’s a plain and factual answer occasionally met with a sense of surprise that the mechanism the British state turns to investigate past decisions and events, usually when something terrible has happened, could be sufficiently interesting for a new play. For me, that isn’t in doubt. I’ve long been fascinated by public inquiries, the hopes and expectations placed in them, and the disarmingly simple questions at the heart of the fact-finding missions: What happened? Why did it happen? And who is responsible? Serving as a kind of pop-up institution, public inquiries tend to be convened in response to major scandals, national tragedies and failures of the state. Some are formed immediately after the events in question; others are decades overdue. There are currently 15 active statutory public inquiries, one of which – an investigation into alleged war crimes by UK special forces in Afghanistan – opened last week. In any public inquiry a tension exists between its function as an independent body determining accountability with the fact that it is constituted and brought into life by the government. Much about an inquiry’s independence and integrity seems to rest on the character of the individual selected by the state to run it – and how they exercise their powers. This is certainly a tension in which the play is interested. One of its central characters is a senior judge at the helm of a long-running inquiry into an environmental disaster. But is this what the play is about? The difficulty in answering this question is that a play cannot be about one thing: a play does not have a topline. In journalism, when working on contentious investigative stories, you tend to want to have a clear understanding of an article’s meaning, particularly when the threat of legal action looms large over our work. Principally, though not exclusively, the risk with publishing stories of this kind is a defamation claim brought by the subjects of our reporting. At the heart of any defamation action is the meaning of the words complained of; if a case goes to court, a judge will determine what in the eyes of a “hypothetical reasonable reader” is meant by the words in question. This scenario – a single reading of meaning decided by a judge – is one we carefully consider and anticipate. As the play has moved from the rehearsal room to the theatre, I’ve found myself attempting to make my own determination of its meaning. Confronted during rehearsals by the theatre’s empty seats, the question of what an audience will make of the play has become inescapable. What I’ve come to appreciate, however, is that a play is radically different from the stories I usually write. The play I’ve written feels entirely distinct from my work as a journalist and resists the kind of questions I’m used to asking of my reporting. I noticed this recently when someone asked me, bluntly: “What’s the play’s message?” This, I think, is the wrong question to ask of a play. For me, drama is not an argument or an attempt to persuade an audience of a set of facts. Theatre can do that brilliantly, but is surely more interesting when it resists leaving the audience with a single easily distilled message. I cannot control what audiences make of the meaning of The Inquiry, yet my hope is that if a judge had to make a determination, their findings would be difficult to reach and deeply contested. The Inquiry is at the Minerva theatre, Chichester, until 11 November