They say it´s a ghost story but it isn´t. As Hilary wrote: a story of time travel, forwards and back, which intrigues the reader with its conundrum, while avoiding its absurdities.

The story moves between the 1920s (when it was written) and the 1770s. There are two heroines, 20th century Jan Challard, a London girl, and 18th century Juliana Clare, the youngest daughter of an aristocratic Berkshire family. Jan is independent and spirited, but leads a humdrum life, works in an office, and walks out with a very suitable young man. Juliana is getting the upbringing of a young lady in the enormous family mansion, Chidleigh, and her life is devoid of excitement and event, to the extent that she struggles for hours to work out what to write in her mind-improving journal. She is 17. Both girls intrigue and ultimately irritate those nearest to them by periodically being mentally absent.

The two heroines can see one another from time to time, momentarily, through some rent in the fabric of time, but never manage to meet and interact. Their lives converge: Jan goes on holiday to stay with her sister close to Chidleigh; and Juliana’s life is turned upside down by the death of her father, and the return of her mysterious brother to take the title and be head of the family.

Lucian Clare is 26 years old, has been away from home since he left it for the Grand Tour 11 years earlier. His notorious dissipation and wickedness caused his choleric father to bar him from the house and contact with the family, and denounce him from his deathbed. But now his father is dead, and he is back. He has been everywhere, learnt everything, tried everything. He has been a leading light in the Hell-Fire Club, tasted all that has to offer, and is jaded and so very bored. His two brothers, chips off the old block, are baffled and resentful, but in his sister he recognises another ‘old soul’, and comes to understand that she has an abundance of a supernatural power of which he has only a shred. He has caught a glimpse of a girl in London, in a dream, or some other altered state, and he wants, through Juliana, to reach out to her. It is Jan, and she is no longer in London, but, as he has, she has come to Chidleigh.

And that is as much of the plot as I’ll tell you. This is such an elegant little novel. The author, who wrote some of the indispensable historical novels of my youth, such as Young Bess and The Gay Gaillard seems less sure-footed in the 20th century. Her independent young heroine seems a little charmless, and her treatment of her family and her poor baffled boyfriend ungracious. However, when I think of the novel’s date (1924), she is writing of a new creature, almost, a product of the First World War, a woman working in an office, asserting her independence, seeing marriage as a choice that she can make, not an inevitable stage in her life. For its time, its almost what one would call edgy.

But at least two-thirds of the book takes place in 1779, and Margaret Irwin moves through her chosen 18th century world as naturally as breathing. Her narrative is cool and light and yet laden with perception. She is wonderful on the costume, manners, rooms and landscapes of the time. She is elegantly economical with a large cast of characters, deftly drawing them in a few strokes, telling you all you need to know about one young lady in the addition of puce ribbons to a crimson gown. She manages to hint stylistically in her dialogue that these characters inhabit a different age, without resorting to full-on archaism. At time, so wonderful are her powers of description that it felt like reading as synaesthesia – the words conjure up colours, light and atmosphere so strongly. Finally, she manages a slow, infinitely subtle building up of tension, violence, and ultimately horror, with breath-taking skill.

This is a tiny book about of 200 pages. I found myself this time speculating on how long it could be, and probably would be today. There are characters with back stories that we do not learn. We are not told in graphic detail what Lucian got up to in Medmenham with the Hell-Fire Club. We do not wander with Jan on her holiday in between her journeys back in time. Thank goodness for that: it is a perfect little lost treasure of a book.

As Moira was, in the case of Whistle Down The Wind, I was astonished to discover that this book is currently out of print. It is easy to find a copy on one of the online marketplaces, though. My copy is a precious 1963 Peacock edition, that wonderful series created by my heroine Kaye Webb of adult titles for young readers. How pleased I am that I was trusted with it.

This is a book to lose yourself in, to read in one delicious afternoon, by the fire, in the ghost story tradition, perfect if you don’t want to be made to jump out of your skin, but be led gradually into a unique supernatural world.