The sun went behind the clouds starting to mass on the hills that rose in stately lines towards the Peaks. The girls set up a clamour of protest as their mother called to them that their swimming lesson was over, but it was largely for show – a little breeze was now ruffling the surface of the water and raising gooseflesh on skin.

The children were bundled in linens and ushered away towards the house, where hot water in ewers and a fire in the nursery awaited them, while Herr Rosenstein, drops of water glinting on his lashes, accepted a towel and wrapped it around his neck and shoulders. Charlotte noticed that wet, his brown hair turned a shade closer to black. His bare feet were narrow and the colour of bone. Encased in wet clothes, his body seemed both more solid and sleek than usual, and she found her own skin prickling in sympathy with his. There was a curious sense of having witnessed him stripped of a layer that had nothing to do with clothing and more to do with having watched him at play in the water; she found herself wanting to stare at him at the same time as she was suddenly shy of doing so. For the first time, she wondered what age he was; clearly younger than she had first surmised.

She looked over at Lizzy, who seemed to feel no such curiosity; she was offering Herr Rosenstein the services of a footman to help him out of his wet garments, and he was demurring: ‘Thank you for your kind attention, but there is no need, Mrs Darcy. If my fire could but be made afresh, that would indeed constitute luxury.’

Even though Charlotte repeatedly apologised for the encroachment on Herr Rosenstein’s time, he willingly repeated this lesson every fine afternoon for the rest of the week – including one memorable day when the trio swam in the grand lake, rejoicing in the spray from the fountain – until both girls could dog-paddle themselves to the nearest bank unaided. Charlotte no longer had to suffer too much anxiety when her daughters chased each other along the banks of the river or around the ponds.

One evening that week, Charlotte went to bid her daughters goodnight and, to her surprise, found Sarah fretful. Laura, worn out by the day’s excitement and exertions, was already sound asleep, but her sister clung to her mother and was inclined towards tearfulness. This behaviour was not characteristic of her dreamy and stoic daughter, and Charlotte, with an internal sigh, knew she needed to get to the bottom of the matter.