The Dashwoods are surprised by the many invitations they receive in Devonshire, including several private balls at Barton Park. Marianne spends almost all of her time with Sir John Willoughby, who seems to have eyes for her alone. Elinor, however, is concerned by how open her sister is in her affections. She, unlike her sister, has no one whose company she truly enjoys, with the exception of Colonel Brandon. He, disappointed by Marianne's ardor for Willoughby, asks Elinor if her sister believes in "second attachments." Elinor must confess that Marianne's romantic sensibility seems bent on the ideal of love at first sight.
One morning, while Elinor and Marianne are out walking, the younger sister reveals that Willoughby offered her a horse, as a gift. The offer thrills Marianne, but Elinor gently reminds her sister how inconvenient and expensive the horse would be to maintain. She also tells Marianne that she doubts the propriety of receiving such a generous gift from a man she has known so briefly. Marianne insists that it does not necessarily take a long time for people to get to know each other well, though she ultimately concedes that owning a horse would be too much of a burden on their mother, who manages the household.
The next day, Margaret reports to Elinor that she saw Willoughby cut off a lock of Marianne's hair and kiss it, a sure sign of the pair's engagement. Elinor, nonetheless, warns her little sister not to jump to any conclusions.
Mrs. Jennings somehow learns that Elinor had affections for someone back at Norland. The old busybody tries to get Elinor to reveal the name of this "favourite," but Elinor insists that she had no such attachment. Finally, however, Margaret confirms that there was such a man, he was of no particular profession, and his name began with an 'F'. Elinor is extremely embarrassed by her sister's indiscretion.
The Dashwoods, Colonel Brandon, Willoughby, and the Middletons plan an excursion to Whitwell, an estate twelve miles from Barton belonging to Colonel Brandon's brother-in-law. However, just as they are about to set off, the Colonel receives an urgent letter calling him to town immediately. This disappoints the other members of the party; they encourage Brandon to postpone his trip, but he insists on leaving right away. He refuses to reveal the reason for his sudden departure, though Mrs. Jennings whispers to Elinor that she suspects he must attend to Miss Williams, whom she identifies as his natural daughter.
Since they cannot go to Whitwell without Colonel Brandon, the party instead decides to drive about the country in carriages. Marianne later confesses that during this excursion, Willoughby took her to his home at Allenham while his elderly relative, Mrs. Smith, was out. Elinor is appalled by the impropriety of such a visit, and she chastises her sister accordingly.