Just before his production of Phèdre followed him on to the screen — well, actually on to 70 screens in Britain and another 200 abroad — Nicholas Hytner told the watching zillions that NT Live was an experiment, a risk, an event that he wasn’t at all sure he would enjoy. The National’s director shouldn’t be nervous or apologetic now. Last week was the first time that a performance in one of his theatres had gone simultaneously cinematic. It won’t be, cannot be, must not be the last.

I went to the 16-screen Cineworld in Stevenage, a town where, if asked to choose, some people might think Racine a rat poison rather than a French dramatist. But it wasn’t just me who thought the experiment a success. So did an audience that nine-tenths filled the 230 seats of screen 13. “Terrific, tremendous, I wanted very badly to clap,” one man told me in evident envy of the applauding punters at the Lyttelton.

True, that mysterious give-and-take, the sense of sharing that ebbs and flows across the footlights, was missing. In Stevenage we weren’t part of the experience and so did not have the tiniest impact on Hytner’s cast. Yet nobody could miss the fact that, led by Helen Mirren as the queen besotted by her stepson Hippolytus, a particularly intense, powerful performance was unfolding in London and, indeed, in theatrically undernourished Stevenage.

Maybe the sound people had over-miked the play. Maybe the camera operators opted too often for close-ups, too seldom showing the stage as a whole. Yet that produced some stunning moments: Stanley Townsend’s magnificent Theseus isolated against a stark blue sky as he terrifyingly cursed the wrongly accused Hippolytus. And there were subtleties you’d miss even from the front stalls: hands like wizened claws as Margaret Tyzack’s Oenone embraced her beloved mistress Phèdre, the sickened disblief on the face of Dominic Cooper’s Hippolytus as his stepmother confessed her passion, the tiny wrinkles on yellowing cheeks that made it sadly clear his would-be mistress was twice his age.

Phèdre was a daring choice for NT Live’s start. It is over-the-top even in the theatre, which should mean that it’s in-the-sky for that realistic medium, the cinema. And some critics found Mirren too stylised at the Lyttelton. Well, the actress staggered, wailed, fell to her knees, embraced Hippolytus’s ankles, yet somehow remained emotionally true. And when she said “I stink of incest and deceit”, you could almost smell that Stygian mix coming from pores that you could actually see.

At the National, Mirren’s yearning and self-contempt were unforgettable. So they were on screens in Clapham, Cardiff, Guernsey, Falkirk — and, yes, Stevenage.

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