Remember when getting Covid meant you had to stay in for seven days? For most of us, it was a week of emotional suspended animation.

Coco Cottam’s new play, Wishbone, is anything but that. It takes those seven days and turns them into a rollercoaster revelation of the relationship between two people, Ro and Ti. Moments before they test positive they are on the verge of breaking up. But at that instant of crisis they are forced to isolate with each other, and over a week of Scrabble, ravioli, shared memories, and ultimately a shared bed, they – maybe – begin to rediscover what they mean to each other.

It takes courage to publicise your new drama with the words, “It’s a play about being mind-numbingly bored”. But for a show in which ostensibly nothing much happens, Wishbone is gripping, funny, and at times heart-rending. Each of the seven days of isolation makes a distinct vignette: one day is done as a rear-projected animation with speech-bubbles, another is almost entirely a monologue from Ro on the phone. One day they’re driving each other mad, the next they can’t keep their hands off each other.

The two performances from Rosa Calcraft and Kaitlin Horton-Samuel are brilliantly assured, and they navigate through the sensual tsunami with charisma, passion, and chemistry so strong you can almost touch it. And the writing is just wonderful. At times Ro and Ti talk over each other just like real people, and their exchanges sparkle with fun and frustration, as when they're arguing about board games:

RO: Sudoku – I could easily beat you in Sudoku.

TI: You can’t beat someone at Sudoku, it's not a winning sport.

RO: Sport!

TI: Yes, this is a sport. There’s holes, there’s manoeuvres.

RO: That makes picking my nose a sport.

As with Coco Cottam’s last appearance at the BT (in Women You Know) the focus on relationship comes at the expense of narrative development. I’m not saying we need more of a story. But it would be great to unpeel the characters a little more, learning more about them as you go. In Wishbone the unpeeling is there, but it feels like the outer layers being taken off, without ever venturing too deep.

With that minor cavil in mind, I’m going to add this to my (very short) list of good things to have come out of the pandemic. It now contains:

1. Sheep wandering freely through the streets of tourist-free Lake District towns.

2. People having international meetings on Zoom rather than flying thousands of miles.

3. Wishbone.