Nicola Walker's Annika proves breaking the fourth wall still packs a punch

Firstly, in the title role is Nicola Walker, one of those blessed actors who, for something we’ll sum up as charm, is always excellent, despite being always the same. Great face, great voice, great timing and palpable compassion – why change?

Secondly, our heroine’s private confidences to camera, from her very first line – "Call me Annika" – to the thrilling season 1 finale when she told us – just us! – who her daughter’s father is (told you it’s complicated).

In between, I laughed out loud when a conversation with her daughter went predictably pear-shaped, and Annika looked to us for sympathy: "I’m now going to justify my mothering strategy," she announced wryly. In the hands of an actor as nimble as Walker, this kind of intimate, knowing exchange only makes us warm to her more.

"Breaking the fourth wall" for characters to confide their innermost thoughts to the audience has been part of drama from the theatres of ancient Greece to the forums of ancient Rome (think Up Pompeii!), from Shakespeare to Miranda via Malcolm in the Middle.

In the mid-1980s, Ian McShane’s wink-tipping antiques dealer was even deemed ripe for parody by the Spitting Image folks. They created a Lovejoy segment and called it "Clichéd Monologue to Camera" – not that this seemed to faze the title star unduly; the show drew big audiences for six seasons and McShane later got to keep the puppet, leather jacket and all.

Lovejoy regularly bestowed a wide-eyed gaze in our direction. "Well, what would you have done?" he appeared to ask, showcasing the enduring appeal of such a stagey device.

For sure, it would never work with shows dependent on our rapt engagement with plot, such as The Crown or Happy Valley.

Imagine if Line of Duty’s Superintendent Ted Hastings suddenly directed one of his Belfast bons mots straight to camera? There’d be no coming back.

What breaking the wall offers instead is intense engagement with one personality, a reason to care. Hence, we meet Annika’s team through her eyes, just as we surveyed the people of Bel-Air through the private musings of Fresh Prince Will Smith.

It requires great acting chops to pull it off, it doesn’t always work and can appear a gimmick when it fails. I’m not convinced we needed the straight-to-camera asides from Bruce Willis and Cybill Shepherd to establish the brittle chemistry between Moonlighting’s David and Maddie; however, two flawless protagonists prove just how powerful it can be.

House of Cards’s Francis Urquhart was a silky-voiced sycophant to his Westminster coterie. Only viewers got to meet the devil within, actor Ian Richardson seamlessly toggling between his two worlds. Surely we would have been more judgemental of his maleficence if we hadn’t delighted in being his trusted confidants or even conspirators.

The prize must, however, go to Fleabag. Like Richardson, Phoebe Waller-Bridge’s title character danced a ballet between her exterior and interior lives, and what began as a hilarious juggling act became a poignant exploration of fragile mental health as the two clashed.

It was a masterful marriage of medium and message, and also a reminder that we all ride these two horses. Sweetly, her private interactions became rarer as Fleabag gradually found a way to exist in the real world with less need of us, her imaginary friends.

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The second series of Annika begins with a double bill on Wednesday 9th April at 8pm and 9pm on U&Drama.

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