‘The State gave an order. We obeyed the order. Everyone obeyed the order. And the world changed.’ In south London, a novelist (not entirely unlike Philip Hensher) and his husband walk to the gates of Battersea Park and back, as far as their government-sanctioned hour of exercise allows. He is suffering from writer’s block, but not for a lack of source material. There are the neighbours for a start: lockdown-busting Gio and his rambunctious extended family, the jogger along the street on the brink of a breakdown and Neil, the local Stalinist and oddball.

And, where the words won’t come, there are compensations: the novels of Ivy Compton-Burnett, the comforting daily ritual of making buckwheat bread and the sound of birdsong. ‘Was this the most beautiful English spring? Or were we finally seeing what was always there?’ the narrator asks. How many of us had similar thoughts?

The pandemic has prompted a spate of novels, and more will no doubt follow. Few are likely to capture so well the strangeness of that historical moment. Infused with the restlessness of lockdown, To Battersea Park is playful, philosophical, sensual (so much food!), violent and funny, often at the same time. But above all, it’s defiant: an account of confinement that refuses to be confined, in which freedom may be obtained through the exercise of imagination and empathy. These being the tools of the reader and writer, the book also serves as a declaration of faith in fiction’s moral purpose – though don’t let that put you off.

In the first of four sections, ‘The Iterative Mood’, the novel addresses directly the challenges of writing about lockdown. Where’s the drama in ‘habits … more regular than those of a wild animal patrolling its narrow territory’? How does a writer ‘say what it was like to move through this arrested time, like an eel through mud’?

While narrative may temporarily fail him, Hensher’s narrator can’t stop naming and noticing things, exercising his curiosity like a bodybuilder putting in the hours at the gym. When he’s not examining the rug by his bed (‘Qashqai’), he’s breathing in the perfume of the garden after rain (‘petrichor’) or chancing upon a pair of exotic trees (‘pomeloes’) exotically trespassing on a Battersea housing estate. Meanwhile, the claustrophobic landscape of his daily walk yields geographical riches, among them a hidden river and a palimpsest of ancient wetlands and woods.

Like one of the closely observed roses in the narrator’s garden, from its confined beginnings To Battersea Park buds and unfurls promisingly. Noticing things leads to noticing people. And, from noticing people, it’s a short step to speculating about their unseen lives. What led to the explosive family row outside his window? What drives the depressed jogger’s son – a fellow noticer – to wander the street with a copy of The Observer’s Book of Trees?

Novels are, as one of To Battersea Park’s many minor characters observes, about consequences: ‘One small thing happens out of nowhere; something else happens; another thing, and another, and at the end of the chain, the world ends.’ In the book’s second section, ‘Free Indirect Style’, Hensher catalogues one such chain of cause and effect. A builder’s wife is having a bad day and refuses to pass on a message, so an old man trips on a broken stair rod and is hospitalised, which forces his son – the novelist from the first section – to undertake a train journey in the middle of the pandemic. Actions have consequences that spread like a virus: we are all connected. In other hands, this might appear a truism, but Hensher’s game of Only Connect is anything but mechanistic, while his talent for social comedy, whether it involves a disastrous Zoom meeting or a gay orgy, is put to excellent use. Nowhere is this more evident than in the novel’s unsettling third section, set on the Kent coast, which offers the most convincing vision of suburban apocalypse since Shaun of the Dead.

It’s not necessary to be an anti-vaxxer to recognise that the pandemic led to the greatest restriction on individual liberties in the UK since the Second World War. Inevitably, freedom and its denial are central themes of To Battersea Park. How do you find autonomy within marriage, family or work? Or break the shackles of fear? Many of Hensher’s characters struggle with these questions in one form or another. But for some, the pursuit of liberty leads to violence, notably a terrible act of self-harm and a murder reminiscent of that committed by Camus’s outsider on the beach.

For Hensher, freedom is the opposite of solipsism; it is the novelist’s openness to the world and the possibilities of other people. It’s significant, then, that the story should close with the boy William, the book’s other great ‘noticer’. Unexpectedly freed from oppressive parental expectation, he opens his front door to find a flooded world and a lifeboat. ‘He did not know where he would go after Battersea Park, but the dinghy would take him there. And then when he was done … he could bring it back.’ What better description of the freedom granted by imagination?