Victor Hugo’s delicate pen-and-ink sketches radiate charm. They draw you in, demanding closer attention. It is not so much the quality of the draftsmanship, although the quality is good enough. Their appeal lies in their composition. Produced in private by this remarkably creative man, more than 4,000 precious drawings are held in archives around the world. Terrifyingly fragile, these works on paper are rarely shown and were last exhibited in London in 1974.

Hugo’s art was first revealed to the public in 1888, three years after his death, and it captured the attention of a long list of artists and writers, including Max Ernst and André Breton. Vincent van Gogh, in an 1890 letter to his brother Theo, described Hugo’s drawings as “astonishing things,” and it is those words that form the title of a show that opens next Friday at London’s Royal Academy of Arts—“Astonishing Things: The Drawings of Victor Hugo.”

Sarah Lea, an art historian and Royal Academy curator, has selected 70 works on paper for the public to puzzle over. After this low-lit exhibition, they will remain in a darkened drawer for five years.

Hugo, photographed by Nadar in 1884.

Born in Besançon, France, in 1802, young Hugo was a renowned poet before he left school. In 1822, M. de Châteaubriand hailed him as “l’enfant sublime.” In adulthood, his accomplishments expanded to include best-selling novels, sensational plays, politics, and, while in exile, activism. Hugo had a rare instinct for popular emotion, and one can’t overestimate his importance as a public figure.

The Town and Castle of Vianden by Moonlight, in pen, ink, and graphite, 1871.

In private, he regularly sketched. Looking at these personal reveries—which feels like a privilege—it’s easy to see them as a “backstory” to his genius, and almost impossible to resist playing Dr. Freud, especially with the more creative “automatic” works or his watery taches (stain) series. It is more helpful, perhaps, to accept that sketching was part of Hugo’s world; he’d studied it every day at school and continued the practice throughout his life. Lea believes that this was where Hugo went to escape—to find expression without words.

The drawings, often made as gifts for his long-term mistress Juliette, range from experimental doodles that contain hidden messages to immaculately executed pieces of Romantic fantasy, such as The Castle with the Cross (1850). They reveal various preoccupations: nature, historicism, architecture. Hugo loved to embellish the truth and created wonderful Gothic towers and orientalist buildings.

Mushroom, in pen, ink, charcoal, crayon, and gouache, 1850.

Nil desperandum, die-hard fans of Les Misérables! There is plenty of ambient gloom. An engagement with death and the sublime is ongoing, especially in representations of Hugo’s beloved ocean, related closely to his 1866 novel, Toilers of the Sea. And while powerfully and actively opposed to the death penalty, Hugo, curiously, produced detailed sketches of men in the process of being hanged. Monumentally grim, the rarely released Ecce Lex (1854) is in the show. Hugo’s drawings possess a haunting melancholia that reverberates in the mind’s eye for days. Did our hero inhabit and experience his works as he drew them? We will never know.

“Astonishing Things: The Drawings of Victor Hugo” will be on at the Royal Academy of Arts, in London, from March 21 to June 29

Sarah Hyde is a London-based writer