The rocks were meticulously placed; flat smooth stones spiralling skywards into a towering cone. Joseph had never seen anything like it. Certainly not slap bang in Midsummer Place obscuring the crowd-pleasing Frog Bubble Clock.

‘Tall fellow, aren’t you,’ he said, circling the cairn and pinching himself in case he was dreaming. ‘How the hell did you get here?’

Joseph had worked as Head of Security at the shopping centre for seven years: opening up, patrolling the Boulevard in case of trouble, and checking everything was neat and orderly. In all those years he’d never discovered a massive monolith blocking his path.

CCTV footage did not elucidate. Apart from a slight flicker at midnight the cameras showed the centre empty and quiet.

‘Aliens,’ Joseph muttered, laughing anxiously to himself, ‘that’s all that explains it.’

He made several phone calls. Top was the shopping centre management who thought it was a prank until he sent photos. Then a demolition company he hoped would make a swift removal before customers forced to make detours on their shopping journeys made angry complaints. Along with several bemused cleaners, he placed cones around the perimeter and large and urgent signs telling people not to climb. Then he rang his wife, who he knew would be sipping her early morning cup of tea in bed, the cat at her feet.

‘It’s all on the radio,’ she said.

‘You what?’ said Joseph bemused.

‘Piles of stones, sprung up on each of the four roundabouts nearest The Centre.’

‘By piles, how big are we talking?’

‘Well, a few feet.’

‘They’ve got nothing on this.’

When he returned to the spectacle, a crowd had formed. Retail assistants, coffee cups in hand, were stood either gawping or taking photos. He overheard at least two trying to sell their stories to the Daily Mail. He attempted to shoo them on, but he wasn’t their boss and had no jurisdiction.

‘Bound to be Druids on Midsummer’s Day,’ he heard one of them say. ‘Ancient lay lines, ain’t it.’

‘I reckon its Banksy.’

‘It’s some sort of stunt, anyway.’

‘Costly,’ was all Joseph could mutter.

At 10am, workmen arrived conspicuous in high vis, whistling through their teeth. Employees, early morning shoppers, and crowds drawn by news reports were too fond to see it unceremoniously dismantled. Fearful of the mood turning, and at management request, Joseph extracted an exorbitant quote and sent the men on their way.

By the time his shift ended, despite the large-fonted signs, the stones shone from people touching them hoping for fertility, virility, good luck, and prosperity. Three faith groups had arrived in robes and sung. A vicar had blessed it. The cairn was trending on all social media platforms. Management were contemplating taking ownership.

The next morning Joseph opened The Centre, apprehensive at what he might find. More towers? An altar? A sacrifice? Instead, he found nothing, not even gravel on the shiny floor.