Miranda Raison and Shaun Evans in Hello/Goodbye
Miranda Raison and Shaun Evans in Hello/Goodbye
© Manuel Harlan

"That sounds surprisingly like an adult conversation" remarks the heroine late on, thereby putting her finger on the key problem with Peter Souter's debut stage play. It's a romantic comedy, short and sweet, but built upon an excess of banter that grows mildly irritating the longer it lasts.

Alex (Shaun Evans, he of Endeavour) finds out the hard way that he's double-booked a flat to rent when Juliet (Miranda Raison, she of Spooks) roars in on a wave of indignant expletives. That's part one, the Hello act. After the interval we fast forward ten years and watch their bittersweet Goodbye.

Evans wears glasses to show he's a nerd; Raison has Phoebe hair to show she's a kook. The actors, beautifully engaged if not always ideally matched for tone and style, carry the audience along and redeem a play that in lesser hands would be very thin gruel indeed.

It's a neat conceit to construct a play on the first and last hours of a relationship. If Harold Pinter covered some of the same ground in Betrayal, the tone of Hello/Goodbye is more that of early Alan Ayckbourn. However, unlike either of them Souter dots every i, then goes back and dots it again till it pierces the page. Alex tells Juliet she's rude and bad-tempered, and then he repeats it – numerous times. She calls him Rain Man, he retorts that she has no friends, and on it goes. Play, rewind, repeat. Neither does it help that so much exposition is handled through dialogue. If I hadn't known Souter writes radio plays I'd have assumed he wrote radio plays.

Hello/Goodbye opened last year in Hampstead Theatre's experimental Downstairs space, and in restaging it for the main house Tamara Harvey has aimed to retain the play's intimacy by wrapping the audience round a thrust stage. She and her design team keep things simple with little clutter and no more intervention than is absolutely necessary – just enough to accommodate Evans and Raison's dysfunctional games of verbal ping-pong. Luke Neal pops in for a brief cameo in Hello, Bathsheba Piepe contributes a slightly more substantial one in Goodbye, but this is very much a star vehicle for the central pair.

If I've made it all sound rather disastrous, that's not entirely fair. There are plenty of well-earned chuckles to be had along the way, not least a delightful exchange over a thermostat. It's just that false notes are never far from the surface. Even the ending, which is clever and satisfyingly tidy, is contrived.

Hello/Goodbye runs at Hampstead Theatre until 28 February