Watching Phoebe Waller-Bridge in Fleabag on stage is like looking through the wrong end of a telescope. Suddenly the entire Fleabag phenomenon, the stripey T-shirts and dungarees, the near-hysterical adulation, shrinks back down to the pin-sharp moment of its origin, in the shape of an hour-long monologue.
The results of the success that grew from this modest theatrical enterprise are everywhere to be seen: in the women wearing the Fleabag uniform outside the theatre, in the presence in the audience of Andrew Scott and Sian Clifford, Waller-Bridge's co-stars in the two award-laden BBC series that followed, and of Fiona Shaw, star of Killing Eve, the next show to benefit from her glistening talent.
But returning to the stage for a last hurrah, it is still simple and direct. Everything that would go on to become part of the television series is there, but in chrysalis form, before it expanded into a beautiful butterfly. Waller-Bridge, skilfully directed by her friend and collaborator Vicky Jones, sits in a spotlight on a tall chair, in that famous red jumper and skin tight jeans and takes the audience into her confidence.
We begin with the disastrous encounter with a bank manager and continue through the familiar lineaments of a life in chaos and a woman in freefall, obsessed with sex, floored by grief, wearing a wry smile and lipstick, but desperate within. Waller-Bridge's sister Isobel provides a sound design that cleverly highlights vital moments; Elliot Griggs' lighting perfectly captures the shifting moods.
But it is Waller Bridge's writing and performance that create Fleabag's world. Words land with precise comic weight, but also with a relish for their sound, beat and emotion. Each character and situation is exactly encapsulated and what you get on stage – which you didn't on TV – is her vivid mimicry of the people she meets.
When she purses her lips, to show the tiny mouth of her casual pick-up who looks like a rodent, or imitates her dead mother revealing the limitations of her enormous bosom by opening a fridge door or attempting to see something on the ground, she reveals a natural clown's gifts. She displays a physical mastery of space and timing of the kind that suddenly made me think of the stylish slapstick of Lucille Ball, a comic actor of another age but with a similar grasp of what made women of her generation tick. Waller-Bridge also brilliantly milks moments of silence; the long pause while she sizes up her sister's disastrous hairstyle before announcing "Hair looks nice" is a particular joy.
But the power of Fleabag resides in the combination of these moments of pure hilarity with an undertow of sadness so profound that it hurts. Every feeling flits across Waller-Bridge's face; she never overplays anything but she makes us always remember the tragedy that her flawed heroine has brought into her own life. It's a terrific performance, beautifully realised, burnishing the legend that the star has already created. Welcome back.