Character Analysis
Countess Fosco seems to be suffering from a severe case of Stockholm Syndrome, which has resulted in her developing a split personality. We'll let Marian sum it up:
Clad in quiet black or gray gowns, made high round the throat—dresses that she would have laughed at, or screamed at, as the whim of the moment inclined her, in her maiden days—she sits speechless in corners; her dry white hands […] incessantly engaged, either in monotonous embroidery work, or in rolling up endless little cigarettes for the count's own particular smoking. (2.1.2.21)
Eleanor's transformation into the countess is quite disturbing. Especially when you realize that her transformation is thanks to her crazy husband, who pretty much comes out and admits that he's been psychologically abusing her for years.
Countess Fosco isn't just a poor victim though. She actually becomes complicit in her own destruction and a sort of villain in her own right. She steals letters and drugs and kidnaps people with the best of them.
While Countess Fosco is not a likable or good person, she's still someone we can feel sorry for, given the years of abuse that brought her to this point. Also, Countess Fosco is perhaps Collins's most damning commentary on marriage in the book. Marriage for the Countess becomes a veritable torture session that results in her developing a raging case of Stockholm Syndrome and a bizarre fixation on her evil (though hilarious) husband.