Leibniz had dropped onto a bench like a sack of turnips kicked off a cart, and put his head in his hands. He pulled the wig back to expose his bald skull, glistering with sweat, so that the breeze could stream over it. This had only made Caroline more disposed to giggle, as it seemed that her teacher was being comically faint of heart.

Later she had come to understand matters more clearly. Sophie would die one day, and George Louis would be Elector of Hanover, King of England, and Leibniz’s boss. On that day Sophie Charlotte would still be the Queen of Prussia, and Caroline might be the Princess of Wales; but Leibniz would be the strange, incomprehensible man who had too much influence with those ladies who had ruled and humilated George Louis all his life.

Leibniz’s anxiety on that score had increased tenfold a short time later when Sophie Charlotte had suddenly taken sick and died. If he’d been spending a lot of time talking to Russians since then, it might be so that he would have at least one safe harbor in which to live out a future exile.

But Caroline had no intention of allowing that to happen.

THE HERRENHAUSER ALLEE was bedded in a swath of pleasant countryside that had been allowed to grow a bit wild. No one would devote time or money to keeping it up, partly because it was in the flood-plain of the Leine, and partly because it was in obvious jeopardy of being gobbled by any future expansions of Sophie’s garden. So by default it had become a sort of park, shaped liked a folded fan, narrow near the city but broadening toward the Palace of Herrenhausen. The result-intended or not-was that at the outset of the journey Caroline felt pent between a high road on one side, and the Leine on the other. These were equally laden with traffic, f?ces, and flies. But as she rode up the Allee, the road and the river insensibly spread away from her. By the time she got to the place where she could see archipelagos of green fruit hanging in the windows of Sophie’s orangerie, she was riding up the center of a cone of silence, smelling nothing but the freshness of growing things.

A foreign princess paying a call would here swing round the fronts of the Orangerie and other outlying pavilions and enter into a street lined, for some distance, with the summer palaces of diverse noble families. Herrenhausen Palace had started as one of these, and grown. It looked across the road to an older and smaller garden that cushioned the family sepulchre. The visitor would allow some hours to be announced, greeted, introduced, and otherwise processed by the Court before being let into the Presence. Caroline instead nipped in through a side-gate and approached the Palace from the garden side. Her mare knew where to take her, and where to stop, and which of the stable-hands was most likely to have a green apple in his pocket. Caroline was afoot in the northeast corner of Sophie’s garden without suffering her train of thought to be interrupted by anyone. Not for a Princess were idle pleasantries. Caroline could not say hello to some random Countess in a Herrenhausen salon without giving the encounter as much forethought, and as keen attention, as George Augustus would devote to mounting a cavalry charge. If she were to say it in the wrong tone of voice, or give the Countess more or less attention than she deserved, the news would be all over Hanover by sundown, and a fortnight later she could expect a letter from Liselotte in Versailles inquiring whether it was true she was having an affair with Count so-and-so, and another from Eliza in London wanting to know if she had quite recovered from her miscarriage. Better to slip into the place incognito.

This end of the garden, closest to the Palace, was divided into a grid of squarish parterres, perhaps tennis-court-sized. What drew the eye here was not the plantings but the statuary: the inevitable Hercules, Atlas, amp;c. The Gods and Heroes of Rome rose out of a sort of fanatically maintained tundra: boxwood cut down into micro-hedges no more than a hand’s span high and wide, and flowered figures crowded with bees maintaining a continual low hum of golden commerce. It was a fine place for high-strung nobles-to use Sophie’s phrase, the sort who took every fart for a thunderclap-to promenade about for a few moments before darting back into the Palace to regale the court with tales of their wilderness adventure. Really it was nothing more than a roofless annex of the Palace. Herrenhausen rose above these parterres in a moderately impressive way, while its wings, only a single storey high, reached out to embrace them. The central structure of the Palace couldn’t have housed Louis XIV’s gardening implements. A mere dozen windows were distributed among its three floors. But Sophie liked it that way. Versailles was a penitentiary for every person of consequence in France, and needed to be large. Herrenhausen was a place for getting things done, and needed to be small and tidy.

Caroline knew that she had likely been sighted from certain of those windows, and so she turned her back on the Palace and began to march away, following a gravel division between parterres. Shortly she arrived at a high hedge trimmed into a slab-wall, and penetrated it through a square opening. If the garden was a palace built of living things, then the parterres were its formal parlour, whence passageways led off to more private and peculiar spaces beyond. To one side was an outdoor theatre, walled by hedges and guarded by marble cherubs. To the other was the Maze where she had begun her courtship with George Augustus. Caroline, however, went out the back. A row of small reflecting ponds formed a quiet buffer between the front and the back half of the garden. Each was surrounded by a garden plot a little less austere than the parterres. Passing between two of these, she twirled round for a glance back at the Palace. On the parterres she had been exposed to view from any window. Now she was about to lose herself in the garden, and wanted to be certain, first, that she had been noticed. Indeed, a contingent of stable-hands had rushed together with a squadron of porters and footmen at the very head of the garden, where a pair of stairways curved down from the main floor of the Palace to the level of the ground. They were setting the stage for the ritual masque that was played every time Sophie emerged from her dwelling. Caroline only watched it until she noticed herself smiling.

She turned round again and plunged through a higher and darker barrier: a row of trees trimmed to form a wall as high as a house. In the back half of the garden, plenty of mature trees and dense hedges made it possible for her to phant’sy that she was a day’s ride from the nearest building. This part was loved not only by her and Sophie but even by George Louis, who at fifty-four still went riding along the surrounding path, imagining that he was out patrolling the wild marches of some frontier duchy. Here one’s lines of sight, and vectors of movement, were funneled into narrow clefts between stands of trees. Sounds carried oddly, or not at all. It seemed ten times the size of the front half.

A teeming buller had started up back in the woods. At first it might have been mistaken for a gust of wind becoming snared in the branches of the trees. But it grew relentlessly, and began to take on spattering and searing overtones. Somewhere far outside the boundaries of the garden, a man was hauling on a great wheel, flooding buried pipes that conducted Leine-water here. Caroline picked up her skirts and rushed to a nearby intersection of diagonal ways where she turned inwards toward the great round pool that stood in the center of the garden’s darker and wilder half. It had already been brought to a rolling boil. A vertical jet had emerged from a stone orifice in the center and shaped itself into a blunt probe, fighting its way upwards like a sailmaker’s needle pushing through a stack of heavy canvas. As it grew, it began to cast off a mantle of writhing vapor. From here, this looked almost like smoke generated by its rubbing against the air. The jet grew higher and higher until it seemed finally to reflect off the white sky (for the day had become overcast). There it shattered into an incoherent cloud of white spray. The whole garden now was suffused with the roar of the artificial tempest, perfecting the illusion that it was some wild and remote place. The clouds of mist hurled forth by this fountain spread outwards from the pool and infiltrated the corridors among the trees, blurring details of what was near and erasing what was more than a bow-shot away, so soon did things in this gleaming cloud lose their distinctness and fade into the darkness of the trees.