It sounds as though Comer was a “natural” from early youth, and judging by the social-media reaction to her Prima Facie performances so far, the fans are impressed. (“Jesus Christ, what a performance of a lifetime. She is incomparable, outstanding, beyond this realm of talent and passion,” raved one typical tweet.) But theatre requires a complex set of skills, confidence and experience; throw in the pressure that attends the “name” actor being the reason that audiences have shelled out lots of money, and the nerve-straining nature of the environment intensifies.

To see how challenging such a foray can be, we only need to observe the upset that has befallen the current revival of Mike Bartlett’s Cock. A breakthrough star on account of his lead role in Rocketman, Taron Egerton was one of three actors in Marianne Elliott’s production, and the centre of the drama is the sexually indecisive figure played by Jonathan Bailey. Even so, Egerton fainted on the first night, vowed to return, did so, then later bowed out citing “personal reasons”. Could the harsh cock-pit of theatre have been a contributory factor? Nerves in front of a camera can be remedied, but stage-fright, or at least the dread ensuing from high expectations, can strike a killer blow.

Whenever a well-known actor ventures on stage for the first time, or after a hiatus or a surge of fame, the take-the-plunge frisson creates its own drama. One of the most notable belly-flops of recent times was EastEnders star Martine McCutcheon attempting to bring some legitimate Cockney value to the role of Eliza Doolittle in My Fair Lady in 2001; she became a recurrent absentee on account of a mysterious ailment, and a byword for the screen star who can’t deliver the goods in the theatre.