‘What about him?’ Shôn quizzes, pulling Geraint back from the edge of pensiveness.

‘You’re like a dog on heat,’ Geraint jibes.

The track ascends quickly through the terraced vineyards, taking them along uneven pathways that crown the dry stonewalls and up crude, steep steps that connect the terraces. The vines have been recently stripped and most have been pruned back ready for the winter, their few remaining leaves blotchy with red and gold. The grapes, the albarola, vermentino and the bosco wither and wizen in some shady spot, a vital step in the process of turning them into sciacchetrà. The trail takes them past isolated huts that defy the precipitous gradients with stubborn sturdiness. Around these now forsaken vinedresser’s shelters, clumps of prickly pear rear up like tethered, menacing beasts, to deter the inquisitive rambler from exploring. Where the terraces have been abandoned and recolonised by native heathers and squat pines, the maquis has reclaimed the derelict refuges.

Above the vineyards, a sea of white-crested turquoise a thousand feet below them, the path, though obvious enough, is rough. Gouged into the face of the mountain, the original course is obstructed time and again by boulders from rock falls. Where landslides have gashed the sea cliff’s contours, haphazard cairns mark an imprecise direction across the rock fields.

‘You’d think they’d have put a sign up about the condition of the path,’ Geraint carps.

‘There was one,’ Shôn says dismissively, ‘but you’ve got to have a bit of adventure in your life. Besides, the Australians I was talking to last night when you were reading your book said they’d walked it, and once we’ve crossed the ridge we get back onto the terraces.’

Where the vines begin again, the descent becomes vertiginous. Geraint stops every few minutes to curse his new varifocals and their tendency to blur the irregular steps unless he looks directly down at his feet. Pausing on a bluff, he takes in the view: Vernazza, hanging on its rocky spit around an almost circular harbour, looks like a child’s model village, the pink and lemon and ochre of the tall, narrow, green shuttered houses adding to the toy-like quality. Shôn bounds on ahead and after ten minutes or more, Geraint finds him slouched against a rocky outcrop.

‘What do you make of this, then?’ Shôn asks, pointing at a carving in the rock face.

‘Mermaids,’ Geraint quips with delight.

‘That’s what I thought, but…’

‘Right… they’re boys!’

‘Exactly… three cute mermen. I wonder what it’s all about?’

‘Probably some local legend,’ Geraint shrugs. ‘The artist was no amateur.’

‘It’s good, isn’t it?’

They come into Vernazza by a lane behind the octagonal domed church, where washing hangs from clotheslines and spider plants hang low from balconies of potted scarlet cyclamen. They find the small terrace of the Ristorante Belforte at the top of the uneven steps at the end of the harbour wall, just like the fetching older couple they’d befriended on the train from Genoa had described: four tables, decked with pink linen cloths and napkins, polished silver cutlery and crystal glasses that glint in the glorious October sun. Shôn, his scientist’s eye trained to observe the merest detail, gestures to Geraint that they should sit, as there’s no evidence that the splashes from the waves can reach them. Despite Sol’s benevolence since their arrival in the Cinque Terre, Neptune and his sirens have been irritable, the sea choppy… squally even; rough enough for the ferryboats that connect the five villages to have abandoned their erratic schedules and for the smaller fishing boats to have remained at anchor. Waiting for il cameriere – the waiter – whom the old queens on the train had said, with the campest affectation, was molto delizioso, they watch the translucent, azure waves rupture into cascades of glistening diamonds as they fold heavily onto the rocks not ten metres below them.