The paramedics arrive for a fourth time, this time with a backup crew, as the boys huddle in their beds feigning sleep. Lux, Bonnie, and Therese are dead, while Mary is still alive. She ultimately survives for another month, but the community assumes she is as good as dead. Dr. Hornicker, realizing that his diagnosis of post-traumatic stress does not adequately explain Cecilia's initial suicide, suggests that the sisters suffer from a chemical imbalance of serotonin. A blood sample from Mary shows a slightly depressed serotonin level, and she is prescribed medication and therapy. The coroner performs autopsies on the sisters, in accordance with a state law requiring investigation of suicides, despite the coroner's great sadness at cutting into such pristine young bodies.
Ms. Perl, the investigative reporter, hashes together some offhand remarks about Cecilia's spirituality to write a conspiracy theory story that suggests the suicides were part of a pact, an "esoteric ritual of self-sacrifice," timed to coincide with some astrological event. Despite her untenable evidence, the media descends on the neighborhood, oblivious to the Lisbons' grief. Horrified, the boys watch as the television stations narrate and analyze the girls' lives, making huge factual errors and often confusing one girl for another. Worse, most of the neighborhood believes what they see on television. In guarding the sacred memory of the girls' truth, the boys realize that they are alone.
Though the Lisbons do not appear publicly, the local real estate agent receives a call from Mr. Lisbon asking him to put the house on the market, and Mr. Hedlie, the English teacher, is hired to clean out the house. While the Lisbons stay in a motel, Mr. Hedlie systematically clears the house of its artifacts, leaving huge sacks of trash on the curb through which the boys furtively search. Three days later, in a massive garage sale, the house's furniture is sold to out-of-towners, while the neighbors wander and gawk.
Meanwhile, the boys' parents seem able to deal with the tragedy, returning to the routine of suburban life while the boys nurse their horror and memories. The plaque on a bench that originally was dedicated to Cecilia is altered to read "In memory of the Lisbon girls, daughters of this community." No one seems to notice that Mary is still alive. Mary returns home from the hospital to join her parents in the empty house, sleeping in sleeping bags as all the furniture is gone. In the desolation of the days following the suicides, Mr. Lisbon obsessively checks the engine of his car, Mrs. Lisbon wanders the house, and Mary sleeps and takes six showers a day. Once, Mary appears unannounced at a neighbor's house for a voice lesson, and leaves without remembering to pay.
Now well into summer and more than a year since Cecilia's first suicide attempt, the air is thick with a rotten stench due to a chemical spill in a nearby lake. In deference to the smell, the O'Connor family chooses "Asphyxiation" as the theme of their daughter's debutante party, asking guests to arrive in tuxedos and gas masks. The neighborhood boys attend the party to try and forget the Lisbon girls amid the waves of drunken socialites. As they return home at dawn, they see the ambulance one final time at the Lisbon house, its lights flashing. Mary has taken sleeping pills and is dead, carted out on a stretcher. Neither of the Lisbon parents appears.
By an odd coincidence, the cemetery workers' strike is settled on the day of Mary's death. All five sisters can now be buried. The only attendees at the mass funeral of the Lisbon girls are Mr. and Mrs. Lisbon, a gravedigger, and a priest. Because of the huge rush of burials, the priest is exhausted, and can barely keep track of the girls in his mind as he gives their five separate rites. That night, Mr. and Mrs. Lisbon move away. Their house is sold to a new young couple, who begin extensive renovations, and remove all evidence of the girls' existence.