Dixon struggles back up the Welches' driveway after drinking far more than he planned at a country pub. He scouts the perimeter of the house for a way in and notices, through a window, Bertrand Welch embracing Carol Goldsmith. After an initial pang of pity for Cecil Goldsmith, Carol's husband, Dixon attempts to forget what he has seen and manages to get into the house. After unsuccessfully trying to sober up, Dixon heads toward his bedroom, but this requires passing through a bathroom that is in use and he is temporarily blocked. Margaret opens her bedroom door, sees Dixon in the hall, and invites him into her bedroom. Margaret tells Dixon that Johns informed Mrs. Welch that Dixon had probably gone off to the pub.
Dixon uses the bathroom and finds, upon his return, that Margaret has put on lipstick. Touched by this gesture, and by Margaret's help in getting him out of the helpless situation in the hall, Dixon begins kissing her. Dixon worries if he is being fair to Margaret, but he continues to touch and kiss her. As his movements become more heated, Margaret suddenly flings Dixon off of her, stands up, and asks him to leave.
Thrust out into the hallway with his coat under his arm, Dixon finds the bathroom door still locked, and heads downstairs to raid the Welches' liquor cabinet. Dixon drinks half a bottle of port, then goes to his room, undresses, and thinks about his pass at Margaret. On the one hand, he reasons, Margaret wants to have a sexual relationship with Dixon, but on the other, he feels guilty for being involved with her so soon after her suicide attempt. Dixon eventually maneuvers himself into bed and passes out.
Dixon's drunken re-entry into a house full of people provides most of the comedy of Chapter 5. The device of a house full of characters coming and going while trying to hide things from one another is a common occurrence in comedies of manners. Much of the events in the chapter are due entirely to circumstances outside of Dixon's control—not only is he too drunk to really do anything of his own volition, but the house's windows and doors deny him access to places he wants to be, and grant him access to things he wants to avoid. For example, Dixon's inadvertently witnesses Carol Goldsmith and Bertrand embracing through a window, and is unable to get back into his bedroom because the bathroom is in use.
Chapter 5 also marks the beginning of Dixon's choosing his own fate. Before, Dixon was merely trying to get by when it came to Professor Welch and Margaret, but in this chapter he begins to rock both boats. Nonetheless, even though he abandons the party for the pub and hits on Margaret, Dixon remains a passive character. He leaves for the pub so as not to further antagonize Bertrand, and the descriptions of Dixon's pass at Margaret are filled with disclaimers, primarily references to his drunken condition. Therefore, although Dixon is no longer merely the victim of bad luck, and has taken his fate into his own hands to some extent, he is still not quite in control of his fate.
Dixon's pass at Margaret serves to ensure his entanglement with her, as their relationship is fueled by guilt and pity. Dixon spends the time during and after their encounter worrying that he's taking advantage of Margaret, even though she clearly knows what she does and does not want.