Set safely behind iron railings, garlanded casually in wisteria and ivy, it was as perfect as something from a Jane Austen adaptation, its handsome facade marred only slightly by a building site next door.

And yet, for some reason, the house gave me the chills: the many windows both impassive and implacable, the side-run down to the tradesmen’s entrance below stairs sounding a warning to take heed of.

Beware, it said, interlopers aren’t welcome here.

Yet there I was, loitering in the shade of a real palm tree in an enormous hand-carved urn, too late to attend what was called, on yesterday’s WhatsApp thread, a ‘casual kitchen supper’ – a term I’d had to look up to check I’d understood.

When a get-together had been suggested, I’d expected custard creams around a tea urn in a draughty church hall – not a full-on dinner party, or kitchen supper, or whatever on earth this called itself when it was at home.

Held at Nella and Marcus Jackson’s very exclusive home, at that: a couple I barely knew, a couple well outside my usual circle.

Facts I did possess: Melissa taught Nella yoga, privately, hence our invite to help with the street party. The high-powered husband, Marcus, was standing in the upcoming local by-election. We’d met once, at a local fundraiser, introduced by Melissa; he’d been polite but distracted – looking past me to see who else he could charm.

Conversation exhausted, I’d moved on to safer pastures by the time Nella herself rocked up, late after a rumoured meeting with TV executives.

No one could miss Nella: all shaggy blonde pony hair and iridescent smile. Clad in soft tawny fur, tall and glamorous as a film star, she’d glided in, oblivious to admiring glances, slipping her hand girlishly into her husband’s. I’d escaped soon after, never wanting to leave Zach for long.

Now, slowly, I opened the ornate gate, thinking wistfully of my own small flat. The idea of arriving in tandem with my best friend was a very different proposition to arriving at this mansion alone, and I was starting to feel uncomfortable in my own formal frock and high-heels – 1970s open-toed mules I’d snapped up in Portobello Market last year, on a whim: just a little too tight.

Don’t get me wrong, I believed wholeheartedly in the proposed street party, following the disasters in the community – not least the terrible accident at Christmas that had claimed the lives of seven people.

But I could help in other ways, without attending this supper thing, couldn’t I? Even if those ways weren’t entirely clear to me now, no one would notice, surely, if I just slipped away.

‘Hello, lovely!’ The glossy front door swung open above me, silent on slick hinges. ‘So glad you could make it.’

Nella Jackson, in all her gorgeous – if extremely casual – designer-clad glory, framed in the twilight, like one of Raphael’s angels, or a Botticelli goddess perhaps.

Or Amanda Holden on Britain’s Got Talent! I imagined my mother coo; she’d be having kittens in her poky Northern cul-de-sac if she knew the company I was about to keep.