The legacy of The Invisible Man is open ended. The 1897 tale by HG Wells is a thrilling read, but its lasting impact is less as a story than a concept. Where the novella gave us an arrogant scientist roaming unseen across the Sussex downs after violent attacks on the locals, subsequent adaptations have repurposed the idea of invisibility for their own ends. In Leigh Whannell’s 2020 screen version, the invisibility of Oliver Jackson-Cohen in the title role becomes a metaphor for his coercive control over Elisabeth Moss as his abused partner. Like many a gas-lighter before him, he does not need to be seen to be obeyed. For actor-turned-playwright Philip Correia, the vanishing act is an analogy for social invisibility. Played by a brooding Daniel Watson, Simon Griffin is a young Northumberland man heading to a secure unit in Morpeth, thanks to a history of fire-raising. “No one in authority had known anything about Simon Griffin,” says one of his assessors. He has been excluded from school and excluded from society. Behind his illiteracy lurks an awesome intellect, but he is invisible to the world even before turning transparent. His psychiatrist Sara Kemp has the opposite problem. Played by a spirited Kate Louise Okello, she is “too white to be black, too black to be white,” and feels forever visible. She wants Griffin to be seen for what he is but, as the case becomes notorious, finds herself in the spotlight instead. All this is resonant stuff, but rather than drive the action, it mostly sits on top of it. Apart from a vicar who believes the poor are responsible for their own misfortune, we don’t see anyone actively excluding Griffin. Nor does anyone racially discriminate against Kemp. We only have their word for it. It’s not just that Anna Girvan’s production, in which every character is unaccountably bad tempered, is stuck in the psychiatrist’s room when it could be exploring the theatrical possibilities of invisibility. It’s also that, despite the questions of a public inquiry, a TV news reporter and Kemp herself, Griffin and his motives remain elusive – see-through to the last. At Northern Stage, Newcastle, until 19 February, and touring until 26 March. Available online 10–19 February.