Set at the end of 1880, the film depicts the invention of the Vibrator (sex toy). Joseph Mortimer Granville (Hugh Dancy) is a young physician who has difficulty with his occupation due to constant arguments over modern medicine. He gets a job assisting Dr. Dalrymple (Jonathan Pryce), whose practice specializes in the treatment of "hysteria", a popular diagnosis for women of that time. Medical practitioners like Dr. Dalrymple tried to manage hysteria by massaging the genital area, decently covered under a curtain, to elicit "paroxysmal convulsions", without recognizing that they were inducing orgasms. Granville meets Dr. Dalrymple's daughters, Emily (Felicity Jones), and her older sister Charlotte (Maggie Gyllenhaal), a suffragette who runs a settlement movement in a poor section of London.