Helen the narrator gets a phone call in the middle of the night, asking her to come and take care of her awful mother, who suffers from dementia but is still awful.    While trying to give her mother a bath, Helen gets fed up and suffocates her mother with a towel.  Then she washes the body and thinks a bit about the neighbours, her mother’s career as a model, her father’s long-ago suicide, and the time her mother dropped her grandson on his head.  Then Helen’s mother’s neighbour knocks at the door.  Helen doesn’t answer, and the neighbour goes away.

Then she tries to get in touch with her ex-husband, who left her because she broke his dragon statue by mistake.  That is a leading cause of divorce.  She gets him on the phone and tells him that she’s killed her mother.  He promises to come over and help dispose of the body.  He also tells her to stay in the house until he gets there, but she doesn’t feel like it, so she dumps the body in the basement and leaves.

Helen drives off to her best friend’s house, where she sleeps with said friend’s son on a whim.  In fact, she does a lot of things on a whim over the course of the book. Then she thinks about the time the neighbours tried to lynch her mother for not calling an ambulance for a boy who was hit by a car.  (She also remembers the nice neighbour who taught her to drive, and her father saying they were going to move but eventually deciding not to.)

Back in the present, Helen’s ex-husband shows up.  He tells her off for moving the body to the basement, and then they talk about his job.  Then they drive up to Helen’s mother’s house, and they talk about why they got divorced.  Apparently, it wasn’t about the dragon statue after all.  Who knew?  They see police cars surrounding Helen’s mother’s house.  The nice neighbour from the flashback comes up to say hi, and then Helen’s ex-husband drives her to work (she’s a nude model).  You’d think she’d call in sick today of all days, but you can’t argue with work ethic.

Then the police come along to question her, and, at around the same time, her best friend finds out about the sleeping-with-her-son thing and gets angry.  Then Helen and her ex-husband get her house ready for when their daughter arrives, and Helen thinks about the time she threatened her daughter’s abusive boyfriend with a baseball bat.  Then her daughter arrives, and Helen tells her that she slept with her best friend’s son and also killed her mother.  The daughter is somewhat nonplussed.

Then Helen gets a text saying that the police want to search her house.  She sneaks off and meets up with her best friend’s son, who she sleeps with again.  Afterwards, he tells her he knows she killed her mother, because that’s his idea of pillow-talk apparently.  Then she borrows his car and drives to an art gallery she once went to on a date.  Then she drives back to her mother’s neighbour’s house (not the nice neighbour from the flashback; the recently-deceased neighbour who’s been mentioned about twice so far) and writes a suicide note.  Then she finds some of the neighbour’s writing and decides not to commit suicide after all.  Then the police show up.  The end.