In director Tanya Wexler's cleverly disarming comedy Hysteria, British actor Hugh Dancy plays Dr. Mortimer Granville, the Victorian physician credited with the invention of the first electric vibrator. Developed in the 1880's and used to treat a nebulous disorder afflicting nearly a quarter of all women (and women only), "Granville's hammer," as the device was initially called, would be revolutionary in ways that Granville could not have anticipated — as well as, at the same time, quite harmless. Similarly and perhaps just as cunningly as Granville's invention, Hysteria oscillates (forgive the pun) between outspoken rebellion on the one hand and pure triviality on the other, with a sum result of quieting satisfaction.

Maggie Gyllenhaal and Felicity Jones play Granville's alternating love interests, Charlotte and Emily — sisters, in fact, though they couldn't be anything less alike. Charlotte is a firebrand advocate of the working class and a nonconformist: she shows up late to dinner, chews with her mouth open and blatantly prefers shabby aprons over corseted gowns. Emily, by contrast, is "the angel of the house," a Victorian model of womanly virtue that modernist writer Virginia Woolf grew up despising and later criticized as a type complicit in patriarchal oppression — a traitor, in other words, to her own sex.

A large part of Hysteria's fun comes from watching not just the evolution of the vibrator (in the movie it begins as "the feather duster") but also of Granville's metamorphosis from forward-thinking to forward-thinker. Such a revision might seem slight, but this is Victorian England we're talking about, where tensions between post-Enlightenment rationalism and Anglo-Christian sentimentality compromise on an austere and delicate social equilibrium, where every meaningful shift toward the modern happens incrementally, if not undetectably. What's important to remember, the film reminds us, is that the late-1800's was not a period of stagnation but rather of thoughtful, prudent change.

Consequently, Gyllenhaal's character reads like an anachronism. In relief to a Victorian landscape so tidy, so period-y, Charlotte's brand of pro-suffrage, pro-proletariat, pro-liberation feminism flies in the face of temporal logic; by most accounts she is a character who simply could not have existed before the 1960's. Fortunately, both Wexler and Gyllenhaal seem to broadcast an awareness of this. By lingering on Gyllenhaal's careworn-chic features and earnest speeches of self-conviction, the camera watches Charlotte in a way that it watches no other — less for sport and more for a clue to her radiance. Her ability, as the educated daughter of a rich physician, to be simultaneously out-of-place and situated in society, makes her dazzling to watch, though it can also nettle one's nerves. More than once, a suspicious inner voice speaks in unison with characters who say, Oh Charlotte, please be a good girl and stop this "women's rights" madness.

Until nearly the end, Charlotte's story arc actually has little to do with the invention of the vibrator — a detail that suggests we are to read them, Charlotte and machine, as simultaneous inventions. They figure each other in that both Charlotte and the vibrator intend to cure a perceived sickness that cannot be cured because it is not a sickness. The vibrator wants to cure female dissatisfaction with penile penetration by expediting orgasm; Charlotte wants to end poverty by way of charity. We err on the side of these simple solutions to complicated problems because they will be more effective than previously ignorant misdiagnoses.

On that note, however, it's difficult to say whether Hysteria would like to see society's ills remedied or merely ridiculed, or whether it elides a distinction between these two approaches. We all know that romantic comedies — or, more colloquially, "chick flicks" — can be immensely entertaining even when they're bad, but whether good or bad they very seldom teach us anything. (I'm using "teach" in the pedagogical sense, as in imparting knowledge; I don't mean to suggest romantic comedies don't issue moral wisdom — they can, and sometimes do, teach by example.) Hysteria, certainly a romantic comedy, pays such allegiance to the genre as to be radical, perhaps even subversive — if you'll buy that strict adherence to a formal principle like genre can aid subversive content rather than stultify it. In a cheerful and amusing manner, Hysteria provides what is essentially a history lesson with a postmodern twist. "Based on true events, seriously," the opening sequence assiduously underlines for us, and there really is so much contained in that word, seriously. There's emphasis, solemnity and — ironically — humor. It's as if the film were to begin by saying, "This movie will have a happy ending," and instead of giving us one, it shows us how to give one to ourselves.

Be sure to check out our exclusive video interview with director Tanya Wexler.