Heisenberg: The Uncertainty Principle, Wyndham’s Theatre. Photo: Brinkhoff Mögenburg.

So this is what happens when the manic pixie dream girl grows up: she’s just as annoying as she ever was.

Georgie is 42. She’s drawn to Alex, who is 75. She kisses him on the back of the neck when he’s sat on a bench, initiates a chat during which – it later turns out – she lies wildly because she’s kooky like that, and then shows up at his butcher’s shop angling for a date. She’s a chatterbox, hyperactive, unfiltered – oh, for god’s sake, the word that describes her best really is ‘manic’. He’s reticent, self-contained, but prone to bursts of inexplicable crying. His life is ordered, but empty. “I don’t feel, I fucking think,” he growls defensively.

So obviously he needs someone to take him out of himself. And so she takes him out, and she is just so very taken by his adorable eyes…

There is some interest in Simon Stephens applying the tropes of the meet-cute rom-com to two individuals in middle and old age. We don’t see those stories enough, and when we do they’re often unfairly coy about sex. But the older-man, younger-woman cliché is still just so boring, even with the brilliant Kenneth Cranham and the brilliant Anne-Marie Duff (it doesn’t help matters, perhaps, that she’s so youthful looking).

A 33-year age gap is still a yawning 33-year age gap is still a yawn.

Then it looks halfway through Heisenberg that there’s going to be a cynical, cruel twist. Actually, it’s just the mid-movie obstacle, and the way it’s overcome – feigned affection has turned into something genuine! – is the stuff of every rom-com, like, ever.

There’s some lovely writing, naturally, especially about Alex’s love for music, and Marianne Elliott’s direction (this is the first show for her new company Elliott & Harper Productions) is plenty sharp. There are moments of tenderness, moments when the past hijacks the characters painfully. And it’s also funny – Cranham especially is a master of comic timing, making Alex’s short, defensively bewildered responses land with big, big laughs.

Duff, meanwhile, fizzes and spits as Georgie, but there’s no disguising that the character is just massively, totally annoying. We get frustratingly little sense of who she really is – beyond being a compulsive liar – and it’s hard not to feel Stephens has fallen into the trap of mistaking quirkiness for personality. Georgie sometimes just screams! For no reason! Which made me! Want to scream as well!

Heisenberg is also a teensy bit disappointing, in that the grand title leads you to expect some wrangling with theatrical form and scientific theory, a la Constellations or Arcadia or Copenhagen. It does consider the uncertainty principle – that, as is explained in the play, that “if you watch something closely enough you have no way telling where it’s going or how fast its getting there.” The ‘something’ being particles in Heisenberg’s case, meaning vagueness and uncertainty are built into the very structure of our universe.

This applies in various slight, but satisfying, ways to the action. That the universe’s seemingly predictable patterns might suddenly be interrupted by randomness relates to the unpredictable Georgie crashing into Alex’s life, setting it spinning in a new direction. There’s the sense of improbability to their encounters, and also the improbability of ever falling in love: that feeling everyone has, in the thick of love, that’s it’s just so impossibly, giddily unlikely you ever found each other in this big old world.

And the theory tucks in nicely at the end, too: Alex doesn’t want to pin down their relationship – as if not quite observing it, allowing it some uncertainty, is the best way to keep it moving forward.

Bunny Christie’s set is cool – pale walls and featureless boxy furniture slide in and out, up and down, smoothly creating spaces within differing apertures: open, or intimate, or oppressive. It works strikingly well with Paule Constable’s lighting: a glowing backscreen of pure light, pure colour, reminiscent of the absorbing work of James Turrell. But while that often proves strangely heady and moving, the overall effect of the design here remains pretty chilly. Shifting isn’t far from shifty; I didn’t quite trust it, just like I didn’t quite trust Georgie.

To be honest, if this was a play in a tiny studio by some emerging writer, I’d be more forgiving, be more taken up with praising the dialogue and the scientific underpinnings. But it’s two top-tier actors and the ridiculously talented Stephens, launching Elliott’s new venture in the West End, and it feels like it should come to more than this.

Heisenberg: The Uncertainty Principle is at Wyndham’s Theatre until January 6th. For more details, click here.