Following close on his portrayal of Magwitch in Mike Newell’s adaptation of “Great Expectations,” Ralph Fiennes assumes the role of Charles Dickens himself in his own film of Claire Tomalin’s book about Nelly Ternan, the young actress with whom the aging novelist had a little-known affair that ended his marriage. “The Invisible Woman” is a small-scaled but elegant and quietly affecting tale of an intimate relationship that reveals truths about the larger society in which it occurred.

In Abi Morgan’s script, the story is constructed as a long flashback. We first encounter Nelly (Felicity Jones) in the mid-1880s, some years after Dickens’ death, as the wife of George Robinson (Tom Burke), a school headmaster in Margate. As she directs a student production of a play by Dickens’ friend Wilke Collins, her mind returns to the years she spent with Dickens, dodging public eyes by living under assumed names. Her recollection begins with another production—a 1857 Manchester staging of a collaboration between Dickens and Collins where the then 18-year old was brought by her mother (Kristin Scott Thomas) and older sisters—a theatrical family—to play a small role. The 45-year old author, one of his country’s most celebrated men, was immediately taken with the young woman, who provided a strong contrast with his plump, stolid wife Catherine (Joanna Scanlan), the mother of his ten children.

So began the relationship that continued until the writer’s death in 1870. Morgan and Fiennes portray its development in delicate but telling strokes, emphasizing Dickens’ halting advances, Mrs. Ternan’s warnings about her daughter’s honor, and Nelly’s own concerns with propriety, most pointedly in a scene in which Dickens takes her to the house where Collins (Tom Hollander) lives with his mistress (Michelle Fairley) and their child in unwedded bliss—a direct violation of social norms. Despite their attempts at concealing their trysts, the affair becomes grist for gossip, and brings Dickens’ domestic arrangements to a head in 1858, when—in an incident that seems a cliché of melodrama but actually happened—Catherine received a delivery from a jeweler her husband meant for Nelly. There follows a decorous face-off between the two women at Nelly’s birthday party—a scene played with beautiful restraint by both Jones and Scanlan—and a skillfully structured montage showing how curtly, indeed cruelly, Dickens ended his marriage long-distance via a letter to the Times. From this point the relationship is treated more cursorily, with a dramatization of the 1865 railway crash in which the two were involved (which allows Fiennes and cinematographer Rob Hardy to open up what’s a fairly confined story a bit, but also omits the fact that Mrs. Ternan was travelling with them) followed by a sequence showing Dickens installing Nelly in one of the homes she’d live in under false names as Dickens’ mistress for the next five years.

All of this is revealed through the recollections that Nelly makes in 1885 under gentle questioning by the local Margate vicar, Reverend Benham (John Kavanagh), who happens to be a devotee of Dickens himself. The periodic shifts to this later time, which show Ternan, now Mrs. Robinson, struggling to come to terms with the loss of her great, secret love while busying herself with the efforts of her husband’s young charges to put on their play, convey the depth of passion she and Dickens felt—something clearly not duplicated in her marriage. The juxtaposition of these sequences with those from an earlier period makes her a tragic figure, especially since her role in the author’s life was so long suppressed, and Jones manages to capture both the character’s sense of decorum and the yearning that lies beneath the surface.

As for Dickens, there are certainly aspects of his character that, as portrayed here, are less than admirable. His rather callous treatment of his wife and, to some extent, his children isn’t played down. And yet in Fiennes’ superlative performance one also senses the desperation of a man struggling to deal with the realities of fame by escaping constant public scrutiny to forge an oasis of private happiness, at one point burning the letters he and Nelly have exchanged (and he has obviously kept as a treasure) to protect not just his reputation but hers as well. And while, as almost always in film, the creative process itself eludes effective dramatization (watching a writer scribble notes doesn’t tell us much about his inner life), the film is able to depict his genuine social concern—not merely in a lecture asking for donations to assist the impoverished, but in an impressionistic sequence showing a walk he takes through the streets of London, gazing on the underworld of malnourished children and sad-faced adults he would so brilliantly bring to life in his work.

The excellence of Fiennes and Jones dominates, but carefully-etched performances are also given by Thomas, Scanlan, Hollander, and the rest of the supporting cast. This is obviously a modestly-budgeted film, but Fiennes and Hardy mitigate that with their artful compositions and striking use of light and shadow, abetted by the superb evocation of the period managed by the behind-the-camera crew (production designer Maria Djurkovic, art directors Nick Dent and Sarah Stuart, set decorator Tatiana Macdonald and costume designer Michael O’Connor). And editor Nicolas Gaster handles the temporal transitions skillfully.

“The Invisible Woman” manages to tread discreetly but insightfully over territory that might have become the basis for simple scandal-mongering. It not only resurrects figures from Dickens’ own life but gives them some of the richness, humanity and frailty that mark those he created on the page.