At last the week comes when the buds break on the wild cherries and in the evenings (however bitter the air) there is still enough light to walk through the gardens and as far as the urn in the wood. As the days draw out – sudden prodigality of evening light – the walks after dinner grow longer. The trees on our lawns fill, showing a wash of white on stark branches, and all over northern Scotland, the buds break on the wild cherry trees of the uplands. A vast gean tree flowers overwhelmingly, filling the space between the chapel and New King’s College in Old Aberdeen, a marker in the progress of the city’s year. The geans flower on the slopes of the Garioch, looking from the distance like wind-blown remnants of blizzard. Sparser along the field above our house, they look like spindrift on the grass. Our hill-field too has its place in the year: we go up there only in summer to look over the house and down the valley towards the blanched castle of the Hays of Delgaty glimmering white amongst the cherry trees.

Our house turns into the house of the villain in a John Buchan thriller, invisible amongst its trees in its sheltered dip in the valley bottom, a house you’d need field glasses and sharp eyes to find. Great Victorian trees thicken around it as May goes on, and the house sinks into the depths of their greenness. On an evening of mist or thin rain the enclosing trees in front of the house take on an aspect of the romantic ballet, full trees beyond shadowy lawns, the theatrical revivals of the years between the wars. The view from the windows composes around the urn placed in line with the door; evening mists move amongst the leaves and the enclosure of the house is complete, with the only gaps in the walls of green the tardy ash trees which do not even come into leaf until the first warmth of June.

I cannot guess why the Victorian who built this house and laid out its grounds was so fond of ash. For all the delicacy of their leaves, they are the last tree in leaf and bare-branched even as the nights draw out to midsummer. This house was built for a childless couple living alone, as the gentrice of the 1880s understood ‘living alone’. Eight square rooms for themselves, a stove-house for the vine, a shaded lawn and a stand of trees beside the water. The life of one of those retiring households who are the protagonists and victims of the ghost stories of M.R. James, although I do not feel that the hauntings of northern Scotland would follow the pattern of James’s stories.

As the summer is almost without dark, there is barely a region of twilight in which revenants can operate. The ghost story of summer Aberdeenshire would have to be played out in the brightest noon. Days of summer rain and rainy mist drifting above the pines evoke rather nostalgia and regret and the longing to travel. The scene would have to be laid far into the hills, amongst the scents drawn up by the warmth from the bracken and budding heather. Perhaps in the Cairngorms beyond the isolated Hanoverian fortress at Corgarff, where the road up to the Lecht turns away to the north and only a track continues westwards into the high hills. It would have to be a story of a solitary walker acquiring a ragged companion on that track, a companion persistent and archaic in speech even beyond the old forms which survive here amongst the country people. So many young men were killed at the end of that late, half-secret civil war – volunteers from the glens which join where the star fort stands at the head of Strathdon, round the ruined castle from which the Old Laird of Glenbuchat led his men to their destruction.

There are no ghosts in our quiet valley. The dark of the summer which is never truly dark is gentle round the house, posing no threat. In the middle of May we take down the heavy curtains, move the furniture away from the fireplace. The green walls of the room are interspersed with the twilight and the leaves moving green within it. All summer, the long sofa is in the window, and later and later into the evenings, there is enough light to read before the lamp is switched on.

On the 21st of May, the air is still cool and the moon rises into a sky cleared by the cold. The turn of the year: I walk between the birch trees at the edge of the wood, thinking of Russian paintings of the late nineteenth century, whose lines of moonlight among trees match the moonlight casting shadows over my shoulder. I look to the north and for the first time see a pencil-stripe of light beyond the pine trees on the northern horizon, the reflection of the brightness over Sutherland, relentless daylight over Norway. Heavy flowering trees shadow the lawns. In England their blossoming is long over; here they are flowering only now. The cold is retreating slowly: a few potatoes have come through in the kitchen garden, but their tops have been caught by the late frost.

At the end of May, the dark has retreated. We are driving home very late from dinner in a house deep in the hills – mossy fields on the lower slopes, bare granite screes above and a castle closing the view. The wind is full of the scent of new needles on larch and spruce, there are long views downwards from the mountain road. The sky at two on a summer morning is oddly disorienting: east and north are temporarily confused. The northern sky is full of reflected light like torn yellow-azure paper laid on slate-blue paper. And the outlines of the mountains are hardly black. Turning northeast toward Huntly, Tap o’Noth fills the skyline, with its flattened summit and its Pictish fort coming into relief, the flanks of the hill modelled by the first light from the east.

As May turns to June, at eleven at night the tendrils of the vine in the vinehouse stand out clearly against a sky that is hardly dark. The setting sun has moved round to the north, the rising moon full into the south, and the stripe of light on the northern horizon is tinged with colour even at midnight. In the garden, the flowering trees are still distinct, their fallen petals clear on the grass, the outlines of the box hedges are sharp and the tulips behind them are visible in stripes of colour. Midsummer nights of subtle, ambiguous light have come: an endless twilight, the ‘summer-dim’ of the northern islands. You look at your watch and suddenly realise that it is half-past nine when you thought it was half-past six. It confuses even the birds: at nine o’clock, larksong is still bubbling down from the sky, the oystercatchers are whistling, and the buzzards circle, mewing sweetly, invisible in the upper air. The swallows are out catching gnats, and as the dimness comes down, they will be joined by the pipistrelles, flickering through the air like scraps of burnt paper.

And the white nights are upon us. It hasn’t really been dark for the last two weeks. The Queen Anne’s Lace is growing up through the planks of the bridge to the island at the head of the lake. It gets harder and harder to come in – the walk after supper prolongs itself towards eleven and even then, when you go into the big rooms at the front of the house, the windows are still full of reflected light dispersed amongst the leaves moving outside. The northern sky is clear again by two and light enough to see the larch branches in silhouette all night long.

These are the happiest times I have known in my life, these early days of the northern summer, after our friend Andrew has arrived to spend the vacation with us, to pass the long evenings in our company. He begins to leaf through the volumes of Schubert on top of the piano as I settle on the piano stool. ‘Atys’ is the first evening song to come to his hand, with its A minor arpeggios laid out like arches on the page. This is the saddest, most yearning song in his repertory: O if only I were beyond the waters in the brightness at the frontier of evening. It is not a song for this calm evening in early summer, rather for the first days of cold wind over reaped fields, with his own departure for the south coming nearer by the day.

Janey settles with her book on the sofa by the window, the green leaves outside the green-walled room hardly moving behind her. Prompted by the time of day and by the light on the water outside, we choose ‘Auf dem Wasser zu singen’ instead, the accompaniment lapping and rocking under the tenor’s barcarolle:

Andrew sings effortlessly, riding his breath, so that the long-sustained notes, with the lapping accompaniment welling up below them, grow smoothly in volume at the close of every verse as the song moves on to the idea of time flowing like the waters.

It ends with the ripples in the accompaniment dying away into silence.

The choice of another song is almost automatic, dictated by everything around us. The stillness evoked by the song ‘Wanderers Nachtlied’ is at one with the stillness outside the open windows: the breathless quiet of evening.

Towards the end there is little for the pianist to do: drop the left-hand octaves into place and let the open chords – horn-calls very far away – pass smoothly under the thumb and third finger of the right hand, moving with the singer’s rising phrase: Warte nur, ‘only wait’. It is one of those moments when I dare to raise my eyes from the score and see the light catching Andrew’s fair hair as he bends forward to read the last words of the song, with their ambiguous blessing which is also a celebration of the certainty of death.

Balde ruhest du auch. Soon, you too will rest.

He sings true on his note, with absolute concentration, but so quietly now as to be coaxing sound – just – out of the green silence of this June evening so far into the north, in this remote house so lost amongst its trees. But the last note reaches – just – to his only audience, to Janey reading on beside the undimmed brightness of the windows.

Overtones fade; the strings of the piano have echoed the last phrase of the music. A breath of westerly air moves the wall of leaves outside the open windows, bearing the sound of the burn back across the grass. Andrew and I catch each other’s eye and smile, as singer and pianist have done for almost two hundred years, when that same resolving chord has faded away to nothing. I find myself thinking of all those households who have heard these same consonances passing into silence, through the intervening decades, through good times and bad.

I close the score and Janey lays her book aside. We go out into the warm air and the level light, into the scents of the tobacco flowers by the door and the clove pinks in the bed beside the greenhouse. Ink-green shadows are beginning to deepen under the trees on the lawn although the sky is bright to the north.

A long drive in early June, returning north from the Lowlands by the back road up Glenshee, from Blairgowrie to Braemar. Between Perth and Ballater we see no more than five other cars. As the pass rises from Perthshire to Aberdeenshire, we move into a light mist, into the outskirts of one of the clouds which hang on the slopes of the hill. Nobody can have passed this way for hours. On the road at the top of the pass, the deer are all around browsing the moss and roadside grass. Fearless, a stag stands right in the road, turning aside, unhurried, calmly moving away. The last westerly sunlight comes from behind the slopes of the hills on the Aberdeenshire side. It is a scene from the theatre of the nineteenth century, the Naples-yellow flooding softly across the winding road, the upland river, the notch in the hills which closes the perspective.

The sun has gone in by the time we reach Castletown of Braemar. Quiet groups of men, dressed for hillwalking, are taking a turn before bed. For a moment, it is the Scotland described by Andrew Greig in his Return of John McNab: the climbers and hill-walkers drawn together in the daft gallantry of a wager to poach the Crown estates on Deeside, a book of nostalgic bravery and loving evocation of place. The pubs are closing by the time we reach Ballater. Another Greig or Buchan hero is strolling home in the new formal dress of the young Scotsman – the kilt worn with an old Scotland football shirt. Along the still reaches of the Dee, great dreamy lilac trees, heavy with pale flowers, catch at the light of the headlamps. Then, birches and pines on either side as the road climbs to the north and into the next valley. There are light-holding tarns amongst the peat and bracken, the dimming sky held in them the way that the last light hangs reflected in the mirrors inside the house. White things, white harling on the isolated farms and towers, stand forth from the dun for an immense time.

The white nights pass, linger, draw on. I write a quick dispatch by 10 p.m. daylight to my friend in the flatlands of Cambridgeshire:

On midsummer night it was impossible to stay in. With the compulsion that attends the whole north, we desire to be outside to witness the temporary defeat of the dark. The main rooms of the house are lit, candles in refracting girandoles, reflected again in the slab of mirror above the fireplace. Chandeliers and Venetian mirrors hold the light in their edges. Light spills onto the lawns as it must have done on nights of high summer for a century or more. The black dog flickers in and out of the shadows at the edge of the lawns. But brighter than the lights of the house is the reflected daylight halfway up the sky on the northern horizon, and there are streaks of rose-pink and carnation in it – colours which are, magnificently, at once sunset and dawn.

The academic year moves to a graceful close, the students pack and go. Suddenly there are empty car parks and the high street of the Old Town is silent, but for the garden fountain opposite the crown spire of the chapel. Then, graduations, with the proper Scottish flaring of scarlet gowns against grey stone. It strikes me (as it has probably struck every Latin-literate academic in northern Europe one summer or another) that the point of the Gaudeamus Igitur, locally ‘the Gaudie’, which our students sing as we come in, is that it says two completely different things to two different audiences. To the students, presumably in their twenties – though they would have been in their late teens when it was written, it says things are good now, and the future uncertain:

The suspended rhyme is held to the end of the verse: Nos habebit humus – the grave will get us.

To the professors coming in as they sing the last verse,

it turns year by year into a memento mori. It is the university that will stand and flourish, while, like all the generations of Principals, Humanists, Civilists, Mediciners, Regents, Magistrands, Tertians, Semis, Bajans and Sacrists, we ourselves will follow Hector Boece and John Vaus, follow all those whose signatures are on the flyleaves of the books in the old library, to the grave. The young are singing truer than they know.

This year the weather is warm enough for the party to be held in the garden of the lodge, the fine house which was once the town house of the Earl of Huntly, almost the Residenz of a German principality. At the back of the house, a long glazed orangery gives onto the lawn; and rising beyond the garden wall, handsome granite houses built as manses for eighteenth-century professors, or as town houses for courtiers assembled from their remote estates in the hills. A moment of quotidian splendour, the enormous garden in the town, and the groups talking under the great trees.

Inside, a double-handled silver cup made for the university by James Fraser in the 1720s sits on the dining room table. The moony silver gathers the reflections of the garden and the summer and the bright sky into itself, against sombre panelling hung with dashing, infinitely sad portraits of Jacobite lairds as students: periwigs and velvet clothing, impatient, strong young bodies, sword-arms practised and ready to fight. As they did, to their ruin, in 1715 and 1745.

Walking in the warm evening away from the party and down the Chanonry, there are heavy trees as far as the main road, and then the crisp rhythm of the stone high street, swelling out around the Georgian block of the town house. The street is empty in sunlit evening quietness, and the cliché of ‘too quiet’ rises in my mind, as I think not for the first time what a magnificent setting the cathedral and college of Old Aberdeen would make for the opening chapter of a mildly nostalgic thriller.

For all the havoc that the late twentieth century has wreaked on it (and the late twentieth century was at its nastiest when Aberdeen was done over), the city is still defined by its proximity to wild country; a promise expressed by the paintings of snowy castle gardens and wild hills in the art gallery. The Old Town and the university lie near the sea, the golf links, and the dunes. It could be the opening of a fiction by Michael Innes – a motor boat landing on the beach at the impossibly early hour of the summer dawn. Students staying on for summer work, and some younger staff inclined to climbing and hillwalking. Chases down the rides of the pine forests behind Huntly; boots splashing through the streams high in the Cairngorms; perhaps a steam launch exploding in the Cromarty Firth to bring the pursuit to an end.

Without deciding who the villains of such a piece might be, I have driven north out of the city as far as the Garioch, through a flawless evening. The sun is high above Bennachie: the Mons Graupius of Tacitus. A Victorian antiquary with more local patriotism than evidence tried out the theory that Mons Graupius was to be identified rather with the Laverock Hill above our house, and that Agricola had chased the Picts down into the very valley where we live. There was, indeed, a Pictish mound and ditch in the front garden of our house once; but croquet cannot be played with convenience on broken surfaces. The lawn is of luxurious Victorian smoothness, and the mound and ditch are no longer to be seen. We are listed officially as a site of former archaeological interest, a designation which has a melancholy, pleasing lack of distinction.

The true smell of summer is mown grass, but beyond that, the garden is scented with lilies, the yellow Turk’s Caps, the Regale, the old roses, damask and moss. But always, in this northern place, the smell of larch and spruce underlies them all. As the light goes, the lilies will glimmer through the blue; the night is so still that the perfume hangs in layers. Walking by half-light at midnight, we are still out and reluctant to go in. It is hard to sleep with light striking up at the ceiling almost all night long.

All summer, visitors come from the south, from the continent, from the Americas. Depending on age and taste, they roam about during the day with the dogs, shut themselves in a room to write, or lie reading on the long sofa in the window bay; they stay for days or weeks, one once stayed for months. They raid second-hand book-shops; the wealthier of them raid antique shops and return marvelling at the cheapness of what can be found here. They get up picnics on the warm pebble beaches which border the Spey, or expeditions into the far reaches of Glenlivet to walk the track by the burn to the secret college at Scalan. We, meanwhile, get on with our lives, until the household assembles at about seven for a drink and the first moves towards dinner.

And the conversations stretch out for hours in the lucent evenings, by the water with its willows and island, or under the striped shadows of the wood behind the house; under the full, dreaming trees in the gardens, amongst the grasses and rushes which move in the wind up on the slopes of the hill. These are the assemblies of the academy of the white nights.

August’s halfway point is marked, for the secular, by the annual artists’ market at Pittenweem in Fife, and for the devout by the Feast of the Assumption. There are hints and indications that the summer is moving to its end. Montbretia comes out in the middle of August, red as iron on the forge, a sure sign of ending. The Scottish schools go back, and there is the sense of the sudden advance of the dark. Summer moves to harvest, simmer to hairst. The chill in the morning comes. As the week goes on, the guests will shuffle and rustle, as do the swallows about the roofs and on the telegraph wires, and one by one, depart.

The last visitors of the summer come, stopping a night on their southward journey, and we gather a dinner-party around them. As the night comes down, the house blazes like a liner on the dark seas. Perhaps someone goes in to the piano, perhaps Andrew goes in to sing and Dowland’s song for the retirement of the Queen’s Champion spills into the rustling night, or John Field’s E flat Nocturne, whose dignity and melancholy are like time itself passing, or like the water flowing in the dark at the end of the garden, or the disciplined sadness of the weird elegy by Thomas Campion:

We wake early the next morning to thin rain on a rising wind. The candles in the lanterns have burnt out, and a rug left out under the trees is beaded with damp. Suddenly the Rayburn stove makes the kitchen notably warmer than the rest of the house. This large breakfast, so many eating standing in the warm kitchen with the rain at the windows, this dim, heroic hour of departure, is all like an adventure story from the years between the wars, like a chapter in those books of John Buchan’s of which we spoke last night. Then the cars reverse on the gravel and head southward. By lunchtime all the guests have gone, conscious that it takes four hours to drive to Edinburgh. But from there it still takes another hour to reach the border.

The road into England is longer if you travel by the A68, with its view down from the pass into Northumberland, and then the melancholy road by Catcleugh Reservoir with its Victorian pump house and cyclopaean stairway for the run-off. Only then are you near the line of the Roman Wall and coming down into the first true valley by Hexham and Corbridge.

Far away to the south, children play in the shallow water of the river-shores above Exmouth; along the coast of Devon, the little shingle beaches below the stuccoed and trellised houses are almost too hot at noon. We move about our house of cooling stone, beginning to talk about when to bring the heavy curtains down from the attics; when to move the sofa back to the fire.

The last time he stayed out the summer here, Andrew sang on his final night for the three of us alone. There was always an order to these last evenings in the years when he came north for his summer vacations. He sang only two songs: ‘Ye meaner beauties of the night’ in the setting by the seventeenth-century master of the Song School of Aberdeen – a song full of the same luckless gallantry as the Jacobite portraits in the Lodge of the Chanonry. Then his universal loath-to-depart – parting, and shorelines fading behind the ship, and the sea under the night and landfall at last: ‘Farewell and adieu to you fair Spanish ladies’. Then he, too, drove away to the south, taking the last of the summer with him. Just when they take in the last of the barley, and the first migrations begin to fill the windy sky.