Thursday, the narrator and main character of the novel, opens the story by depicting the table she has set for dinner with her husband, Seth. She “shares” her husband with two other women they call “Monday” and “Tuesday,” the days of the week the other two women spend with Seth. The other two women live in Oregon, while Thursday lives in Seattle. Thursday’s day with her husband is, coincidentally, on Thursday, and she welcomes Seth home with open arms and tries to control the situation by seducing him. This plan works, and the couple abandons dinner and has sex.

Thursday takes advantage of the attention and tries to learn more information about Seth’s life outside of the days he spends with her. Monday is pregnant and went for a checkup earlier that week, and Thursday feels immensely jealous about the attention Monday gains because of it. Thursday thinks about Tuesday, a career woman who, Thursday feels, doesn’t deserve Seth. Thursday reminds herself that she is Seth’s legal wife and the only one to whom he is really married, and she attempts to find comfort within that fact. They discuss the possibility of going on vacation together, something they’ve been talking about for a year; Seth promises they will soon.