In the midst of freakishly late snow in the middle of May sometime during the 1840s, Baroness Eugenia-Camilla-Dolores Münster and her brother Felix arrive in Boston from their home in Europe. Having married Prince Adolf under the terms of a Morganatic marriage which allows a nobleman of higher rank than his wife to dissolve the marriage at his pleasure without incurring legal or financial repercussions, Eugenia—ostensibly for the purpose of visiting her cousins—has “come to seek her fortune” in America. By which is meant that she has come to find a wealthy man to marry.
The next day has Eugenia sending Felix off alone to face the unappealing task of introducing the Europeans to their American cousins. A young woman named Gertrude Wentworth is roaming the grounds of a manor in the country, lost in the excitement and adventure of a copy of The Arabian Nights. She is shocked by the sight of a strange—but quite handsome—a man who bows to her in a continental style not often seen in America. Over cake and wine, she is enthralled by the story the man tells her about how his sister is unhappily married to a European Prince and, he suspects, not for much longer.
When Felix returns to his sister later that evening, he is practically giddy in relating his adventure. Perhaps captivated by the possibilities herself, the following day finds Eugenia accompanying her brother to the Wentworth manse. Most of the Wentworth clan betray their wealthy privilege by provincially confusing Eugenia’s haughtiness with a more congenial sense of superiority. Her ability to impress them is not reciprocated as the only member in attendance who strikes her fancy is a cousin named Robert Acton. Upon an unexpected invitation to stay with the family during their visit, however, Eugenia's façade cracks slightly and she accepts while barely able to contain her emotions.
In a private conversation that night, the Wentworths and Acton discuss the details of the invitation with Gertrude forwarding the notion that Eugenia and Felix might prefer a bit more solitude than can be offered within the manor house. At Acton’s suggestion, Mr. Wentworth agrees to extend the offer of a private cottage elsewhere on the property. Days later, the Europeans have already nestled themselves comfortably into the alien environment with the help of Felix’s aesthetic taste for decoration. Felix, already captivated by the general prettiness of American girls, can barely contain his excitement at being in such close approximation to Acton’s gorgeous sister, Lizzie, Gertrude, and her prettier older sister Charlotte. When the two sisters decide to visit the cottage, they are surprised to see she already has a visitor: Robert Acton. A couple of days later, Acton makes another visit, this time accompanied by a local minister named Brand who is far more impressed with Eugenia. For his part, Acton is still trying to work out exactly why a European Baroness would prefer a small cottage in the country over an elegant hotel in the city.
Eventually, enough time passes for Felix to feel comfortable enough to make an unexpected request of his host: he would like to paint a portrait of Mr. Wentworth. He no sooner politely declines than Gertrude makes the offer to be the subject of the painting herself. It takes even less time for Felix to enthusiastically agree. Over the next few succeeding days as Felix paints, while Gertrude sits posing, the two become closer as the topics of conversation become more personal. Gertrude admits that she finds her family overbearing and increasingly unpleasant. When Felix begins reminiscing about his adventures in Europe, it is like having one of her beloved adventure novels spring to life before her. Against her father’s very specific instruction. Gertrude begins to fall sway to the influence of the Europeans.
Almost as if sent to break this spell, one day her pleasing routine of sitting for Felix is interrupted by a strange interlude with Mr. Brand. Accusing her of purposing avoiding him and fearing the worst with the arrival of the handsome European, he decides to openly profess his love. It is not the first time he has made this decision, however, and it is not the first time that Gertrude’s reaction is a stoic acceptance of the fact without feeling any need to demonstrate reciprocity.
Mr. Wentworth has soon enough fallen into a daily routine of paying a visit to Eugenia and more often than not finds her in conversation with his unmarried cousin who it seems has clearly taken a more than polite interest in the Baroness. In fact, their relationship has begun to inch forward to the point of leaving the cottage to take leisurely carriage rides together. The day finally arrives when Eugenia makes it known that she has received a document from her husband, the Prince, requesting her signature which will instantly dissolve their marriage. When she informs Acton that she is very close to agreeing to sign her marriage away, he expresses his hope that she will let him know if she reaches the point of putting the signed document into the post.
After seeing Gertrude’s portrait, Mr. Wentworth agrees to let Felix paint his as well. During one sitting, Wentworth confesses to Felix that his absentee son Clifford has recently received a suspension from college due to excessive drunkenness. Wentworth is taken aback by Felix’s recommendation for dealing with this humiliation: to encourage his son to begin courting the affections of Eugenia. Felix later successfully convinces Eugenia of the wisdom of pursuing this path. Felix also learns from Gertrude of the burdensome expectations placed upon her by her family to eventually marry Brand. This confession is made upon the two spotting Brand and Charlotte alone together. Felix begins to conceive a plan to shift Brand’s affections from Gertrude over to her sister.
That very night Brand disparages her growing friendship with the European aesthete, but Gertrude's response suggests that in wasting his attentions upon her, he might be ignoring someone else who could make him much happier. Charlotte is not amused. Their brother Clifford, meanwhile, is quite amused by Eugenia’s European ways, but clearly has no real interest in wooing her when the gorgeous Lizzie Acton remains available. (Although not immediately so since, ironically, she has recently traveled to Europe.) Eugenia does not find Clifford particularly enticing but decides to keep him around as a backup in case things with Acton do not turn out as hoped.
In the week since letting Eugenia know he is interested in whether the state of her marriage changes, Acton has finally confronted the reality that he might actually be in love with her. Upon reuniting and asking whether she has signed the divorce document, however, she is strangely equivocal. Surprising even himself, Acton’s reaction is to invite her to join him on a trip to Niagara Falls. She agrees and promises to open up completely about the document once there. No sooner has she made this promise than they are interrupted by Clifford who takes one look at Acton and runs off in the opposite direction. Eugenia is forced to confess that the younger man has fallen in love with her. The following day Acton tracks Clifford down to get the full story only to hear Clifford say that he turned and ran because he mistook Acton for his father. When pressed on the key question of his feelings about Eugenia, Clifford makes it quite clear that he is not in love with her.
The following Sunday, Eugenia decides to skip the weekly ritual of attending church with the Wentworths, having grown increasingly anxious over Acton suddenly seeming to disappear. Felix, on the other hand, returns from the services positively buoyant. As Eugenia despondently muses that it is perhaps time to give up seeking her fortune in America and return home to Europe, Felix confesses to having fallen in love with Gertrude. Since her father would not likely give his blessing to their being married under their current unstable economic circumstances, he presses upon Eugenia the increased necessity for her to quite seek her fortune and find it. Eugenia responds that she believes Acton wants to marry her, but she has no interest in marrying him. Felix’s mad Sunday of manipulation continues when he later confronts Mr. Brand and tells him that Charlotte is secretly in love with him and that his insistence of vainly pursuing Gertrude will result only in extending Charlotte’s misery.
The next day Eugenia decides to bid her final farewell to Acton’s dying mother who expresses her desire that Eugenia maintains her residency in the cottage and her companionship with her son. Spotting Acton outside, she announces her intention to leave. Acton is torn because while he is willing to admit to himself that he is in love with her, he still is not sure if he can trust her. When he asks if she has signed the document and dispatched it back to the Prince, she says she has, but Acton still has his doubts. Later that night, Eugenia asks Clifford why he has been visiting her less often than he used to, but his unconvincing explanations lead her to announce to him as well of her immediate plans to leave New England.
While Eugenia despondently heads back to the cottage, Felix is up at the main house confessing to Charlotte his love for her sister and begging her to help plead his case with her father. Later, he finally professes his love for Gertrude to Gertrude who responds that she is ready to do anything it takes for them to be together. A few days later, Felix makes his case to Mr. Wentworth and is surprised that the man's opposition is not based on Felix’s economic state, but on the immorality of his coming between Gertrude and Mr. Brand. Gertrude announces that she has every intention of marrying Felix just as Brand enters expressing his wish that Wentworth gives his blessing to the marriage of Felix and Gertrude with himself presiding as minister. This finally convinces Wentworth to set aside his objections.
Later that night after a celebratory dinner, Acton expresses his hope that Felix’s impending nuptials will be enough to convince Eugenia to delay her farewell. Especially seeing as how she has signed the document renouncing her marriage to the Prince. His tone moves Eugenia into full haughty Baroness mode as she declares that she is not used to having her word doubted. Acton responds by announcing the surprise engagement of his sister Lizzie to Clifford.
Eugenia later informs Felix privately that she plans to leave for Germany on the first available ship. She also tells him that Acton did propose to her but she turned him down. Finally, she confesses to her brother that she lied about having signed the divorce document. True to her word, she arranges passage on the next available passenger ship heading to Germany, but the night before she is scheduled to finally leave the cottage, Acton shows up expressing his wish that she changes her mind.
She does not and Felix accompanies her to the ship where they say their goodbyes. Eugenia heads back to Europe while Felix stays and marries Gertrude before they head off together to adventures unknown, returning briefly only to attend the wedding of Charlotte to Mr. Brand. Clifford marries Lizzie and they set up a home nearby. Shortly after the death of his mother, Robert Acton marries "a particularly nice young girl."