National Theatre | ★★★✩✩

In Beginning, David Eldridge’s unexpected hit of 2017, the playwright charts the difficult birth of a relationship in real-time one night after a party. Middle, which features a different couple in their late 40s and is the second play in Eldridge’s planned trilogy, does exactly what it says on the tin.

Maggie (Claire Rushbrook) can’t sleep and is downstairs heating milk in a pan when she is joined by her husband Gary (Daniel Ryan). It is the middle of the night and their eight-year-old daughter is upstairs asleep, oblivious to the crisis unfolding.

“I’m not sure I love you anymore,” says Maggie. Gary’s evasive answer is that he meant to take the pork out of the freezer. This first exchange illustrates most of what is wrong with the relationship. The following one hour and 40 minutes dissects it.

The title could have multiple meanings. Eldridge explores the middle of a relationship by setting it in the middle of the night and in a comfortable home whose pastel walls and smart furnishings, including a glass cabinet displaying the good crockery, reflect middle-of-the-road tastes. But all this is merely to wallpaper over the cracks.

Maggie is unsatisfied. True, they had sex twice on their recent Valentine’s break; but for her, the second time was just to check that she didn’t enjoy it anymore. Conceiving their daughter was a long process of trying and failing, culminating in IVF. And while Gary was constantly at work toiling to pay for everything he aspired to, Maggie was stuck raising their daughter. She made friends, didn’t she? “Five years of mums,” is her desolate reply.

But all is not lost, promises the increasingly desperate Gary. They can “jazz up” their love life. He has some “bits and bobs” in mind.

Rushbrook and especially Ryan are terrific in a play that needs its actors to cool and warm as the play’s emotional ebb and flow demands. But there are false steps in Polly Findlay’s production. When Maggie confesses to having fallen for another man, a high-achieving police officer whose eldest daughter from an earlier relationship is anorexic and whose wife has an overactive thyroid, the description prompts (presumably) unintended laughter. And whereas in Beginning the possibility of never knowing what might happen creates its own tension, in Middle, leaving what you know seems a lower-stakes game.

But ultimately, this play is about communication. That and the life lesson of reconciling oneself to disappointment. It well conveys how starting up a meaningful conversation for the first time in years is like cranking up a long-seized engine. Middle isn’t quite as compelling as Beginning. Though it is good enough to look forward to End.