I’ve long been a bit sceptical of filmed stage plays, but I’d heard so much about the power of Judie Comer’s performance in this one-woman play that I thought I’d stream it.

The plot concerns a barrister who specialises in defending sexual assault cases, but is then assaulted herself. For the first two-thirds, this felt like an virtuoso performance of a well-scripted but humdrum plot. It felt like a legal equivalent of the doctor-turned-patient cliché, with much the same by-rote conclusions about not giving enough consideration to the perspective of the victim/patient.

This impression wasn’t helped by the sound design, which is also a cliché: heartbeat-driven tension beds, which feel as though they do more to undermine the raw honesty of Comer’s performance than to support it.

But then: that final section! Emotion meets polemic meets rage meets eloquence meets honesty. Never mind the theatre, you could have heard a pin drop in my carpeted living room.

This turned out to be an astonishing performance of an excellent script.

’Prima Facie’ is available to stream via National Theatre at Home until 9 March.