Charles Dickens has an affair

Ralph Fiennes acts in and directs The Invisible Woman.

The most compelling reason to see The Invisible Woman -- a look at a long-running affair between author Charles Dickens and actress Nelly Ternan -- has less to do with the lure of illicit romance than with Ralph Fiennes' engaging portrayal of Dickens, an author of abundant talent, indefatigable energy and dazzling complexity.

In what might be his must spirited performance ever, Fiennes (who also directed) reminds us that Dickens was a self-dramatizing celebrity with an enviable capacity for work. Not only did Dickens write his often lengthy novels, he directed plays, acted, spoke frequently at public gatherings, fathered 10 children and conducted a busy, extracurricular personal life.

When Fiennes reads Dickens' prose to the author's adoring fans, he makes it clear that Dickens keenly understands the drama in his own work. In fact, drama -- sometimes even melodrama -- might be the most important thing to Dickens, both in his writing and in his private life.

The movie's title suggests that Ternan (Felicity Jones) was forced to subordinate herself to the demands of the great man's image. The 45-year-old Dickens was married when he met Ternan, who was 18 at the time of their first encounter. Dickens discovered Ternan while he was directing and acting in an amateur production in Manchester.

According to the movie, Dickens eventually separated from his wife, but never publicly acknowledged his 13-year relationship with Ternan, a woman who (in the movie's view) understood and appreciated him in ways that his staid, portly and mostly resigned spouse (a fine Joanna Scanlan) never could.

In one of the movie's best scenes, Scanlan's Catherine gently concedes the race to Dickens' heart, but warns Ternan that no woman ever will be as important to the great man as his adoring and voracious public.

Working from a script by Abi Morgan -- who adapted a book by Claire Tomalin -- Fiennes alternates between Ternan's life as a married school teacher and her youthful days with Dickens. The structure emphasizes the fact that Ternan -- often seen taking brisk walks on a lonely Margate beach -- is struggling with her past.

Jones tempers youthful enthusiasm with growing unease. Ternan, we learn, is a mediocre actress whose mother (a fine Kristen Scott Thomas) takes on a difficult task: She angles to advance her daughter's prospects while also protecting her.

At one point, Dickens' friend and fellow author Wilkie Collins (Tom Hollander) tries to convince Nelly that she's duty bound to break with convention and accept the role of perpetual mistress. Men, Nelly says, can afford to be sexual pioneers: Victorian women can't.

Toward the end of the movie, Nelly has a conversation with a sympathetic cleric (John Kavanagh), and the movie proceeds to a redemptive finale. Nelly apparently has digested her past, and is ready to move on.

Fiennes has directed before (Coriolanus), but I'm not sure that he's mastered the art of being on both sides of the camera. In The Invisible Woman, his work in front of the camera surpasses what he achieves behind it, despite able assistance from cinematographer Rob Hardy and production designer Maria Djurkovic, who team to create a finely detailed 19th Century environment.

For all of its achievements, The Invisible Woman seems a small potatoes drama, a minor and sometimes sluggish portrait of Victorian womanhood into which the character of Dickens breathes most of the movie's life. I can't know Fiennes intentions, but I find it difficult to believe that's what he had in mind.