This anthology of female-led dramas, written and directed by Dominic Savage, has been an admirable commission. It has served as a reminder of the bold, imaginative programming that made Channel 4’s reputation and which has sometimes been lacking of late, especially in the drama department.

Following a gut-punch performance from Suranne Jones (I Am Victoria) and an underpowered one from Letitia Wright (I Am Danielle), this third and final playlet was propelled by the Oscar-nominated talents of Manville. She played Maria, a woman seriously wobbled by turning 60. 

As the action slowly unfurled across her birthday weekend, the mercurial Maria realised her life wasn’t what she wanted. She was feigning happiness in her 31-year marriage to uptight husband John (Michael Gould) and aching for adventure. They’d settled down young, had a family and made a home, but Maria was increasingly preoccupied by what she might have missed out on. 

First her work colleagues surprised her with a birthday cake, much to Maria’s embarrassment. After an unmistakable frisson of flirtation with younger boss Anthony (Gershwyn Eustache Jnr), she went home and tried to seduce John in the kitchen. More concerned with the spaghetti bubbling on the hob, he was irritated by her spontaneity (“Not now, Maria!”) and rejected her, leading to bitter recriminations.

During a celebratory lunch with their adult children the following day, tension between the couple cranked up to excruciating levels. Maria was dismissive of such birthday trimmings as cake, candles and singing, further hinting at her triggered feelings about ageing. Simmering resentment soon bubbled to the surface. 

The snarky pair sniped with asides like “Here we go again” and “Not this same old story”, demonstrating they’d been here many times before. They wheedled away at one another’s weak spots with the sadistic skill of long-suffering spouses. It led to a deeply awkward meal where somebody exclaiming “Lovely hummus!” came as blessed relief.

It became clear that Maria resembled their free-spirited daughter Alice (Ellie James), who was about to go travelling in Canada, while John was more like son Andrew (Ziggy Heath), who was sensibly saving for a deposit on a flat.

“There’s such a lot I haven’t done,” Maria sobbed on Alice’s shoulder. “I don’t feel remotely old. I feel fit, alive and so full of potential. My life’s not over. I won’t let it be. Because I’ve got a lot to give.” 

Yet she struggled to articulate these thoughts to the prickly, pass-agg John. He got defensive. She felt unheard. Once the children left, Maria gulped down white wine, picked another blazing row and stormed out to clear her head.

She soon returned home, glammed up and hurried out. We next saw her at Anthony’s “bachelor pad”, where their crackling office flirtation inevitably tipped over into passionate sex. The years and worries seemed to just fall off Maria. Somewhat unconventional post-coital pillow talk saw her quit her job. “I want new Maria,” she said, to herself as much as him. “I don’t want old Maria anymore.”

In a near-silent sequence, she did the walk of shame back to her own house, comforted the sobbing John, then appeared to leave him for good. The milestone birthday had pushed Maria’s suppressed discontent into the open, at last giving her clarity. She longed to find liberation and happiness again. And with his bafflement at his wife’s restlessness, her fresh chapter wasn’t going to be with risk-averse John.

In the absence of any inner monologue or grand speeches, Manville’s impeccable performance and Savage’s lighting did much of the dramatic heavy lifting. Close-ups on Manville’s face showed her inner turmoil. She gazed pensively at the sunset, symbolising her sense of time slipping by. In her car, Maria gave a small smile as she emerged from a gloomy tunnel into dazzling sunshine.

As an alumnus of eight Mike Leigh films, Manville is skilled at I Am’s process of semi-improvised collaboration. Naturalistic dialogue felt so authentic that the viewer often felt like they were intruding on private moments. That breathy sex scene might have been surprisingly sensual but the raw marital strife was even more visceral. 

Samantha Morton was BAFTA-nominated for I Am Kirsty in 2019’s debut run. Both Lesley Manville and Suranne Jones might find themselves on the awards radar this time around. This was a perceptive, empathetic look at ageing, marriage and midlife self-discovery. It posed thought-provoking questions, rather than offer easy answers. And in Manville, it had a star in her creative prime.

I Am… is available to watch now on All 4. Visit our Drama hub for more news and features, or find something to watch tonight with our TV Guide.