Mr. Griffin refuses Jeff's request for an assignment extension and threatens to hold students back from graduation.

Mark proposes kidnapping Mr. Griffin to Jeff and Betsy at lunch, suggesting Susan be used as the decoy.

Mark visits Dave at home and convinces him to join the plan to kidnap and frighten Mr. Griffin.

During a picnic at the waterfall, the group reveals the kidnapping plan to Susan, who reluctantly agrees to participate.

Susan keeps Mr. Griffin late after school, and the boys ambush him in the parking lot, placing a bag over his head.

The students tie up and gag Mr. Griffin at the waterfall, and Betsy confiscates his bottle of nitroglycerin pills.

Mr. Griffin refuses to beg his captors for forgiveness, so the students leave him bound and helpless outdoors.

Susan convinces Dave to return to the waterfall, where they remove Mr. Griffin's blindfold and find him dead.

The group gathers after a basketball game and Mark convinces everyone to cover up Mr. Griffin's death and stay silent.

Cathy Griffin reports her husband missing to Detective Baca, who agrees to investigate the disappearance.

Mark, Betsy, Jeff, and Dave drive to the waterfall and bury Mr. Griffin's body.

Cathy Griffin visits Susan's home and directly confronts her about the false details Susan gave to police.

Lana finds Mr. Griffin's pill bottle near the waterfall and reports it to Detective Baca along with a suspicious mound of earth.

Dave's grandmother is found dead at home, and a neighbor reports seeing a young man in a brown sweater inside.

Mark sets fire to Susan's house with her tied up inside; Detective Baca and Cathy arrive and rescue her.

The novel follows a group of teenagers manipulated by the charismatic but dangerous Mark into kidnapping their strict English teacher, Mr. Griffin. Their plan to scare him into being nicer spirals out of control when they leave him bound outdoors without access to his heart medication. Susan and Dave return to free him only to discover he has died, and the group buries the body and attempts a cover-up. A determined police investigation closes in as Cathy Griffin refuses to accept that her husband simply walked away. When Mark resorts to further violence to protect his secrets, the story reaches a deadly climax in Susan's own home. Justice is finally served when Detective Baca and Cathy arrive in time to rescue Susan and bring Mark to face criminal charges.

The kidnapping of Mr. Griffin and its deadly consequences.

Susan helps Dave collect his blown-away homework papers on the way to school, walking alongside her crush for the first time.

Dave drugs his grandmother's Jell-O before school so she will sleep through the afternoon and not interfere with his alibi.

Betsy stages a false alibi by leaving half-eaten cake slices and a blaring stereo before slipping out of her house.

A police officer pulls Betsy over for speeding as she drives to meet the group at the kidnapping location.

Jeff sets Mr. Griffin's nitroglycerin pills on a rock and nearly crushes them while the students taunt their bound teacher.

Betsy recalls how Mr. Griffin exposed Mark for submitting a plagiarized paper and had him removed from class.

Mark's uncle and aunt discuss his odd, secretive behavior at home and wonder whether his traumatic childhood has permanently damaged him.

Dave snaps angrily at his grandmother over breakfast, afraid her sharp memory will ruin his alibi for the previous night.

Mark intercepts Susan before she reaches the principal's office and coaches her on the false story to tell the police.

Betsy and Dave park Mr. Griffin's car at the airport with the keys in the ignition; a police officer recognizes Betsy.

Mark abruptly cuts off Cathy Griffin when she tries to ask him the name of the girl whose paper he plagiarized.

Dave confesses to Susan that he took Mr. Griffin's college ring from the body before it was buried.

Dave's grandmother finds the college ring in Dave's room and becomes convinced it belongs to Dave's long-absent father.

Susan's family reads a newspaper report stating that a small man's windbreaker was found wrapped around Mr. Griffin's body.

Susan's mother reads aloud a clinical description of a psychopath from an American Psychiatric Association publication, and Susan recognizes Mark.

Behind the kidnapping plan lie careful preparations and deliberate deceptions, from Dave drugging his grandmother's food to Betsy staging a false alibi at home before slipping out undetected. Small mistakes begin piling up almost immediately, including a speeding ticket that threatens Betsy's alibi and a police officer who later recognizes her at the airport. The group scrambles to dispose of evidence and stay ahead of the investigation while cracks form in their stories. Cathy Griffin proves a formidable adversary, pressing for answers and exposing inconsistencies in the students' false accounts at every turn. A trail of overlooked details — a man's jacket, a missing ring, a recovered pill bottle — slowly and inevitably connects the teenagers to Mr. Griffin's death. By the story's end, Susan's mother helps her understand the true nature of Mark's psychopathy and what must be done to pursue justice.

The preparations, small mistakes, and unraveling cover-up behind the crime.

Jeff remembers watching a young Mark set fire to a cat in middle school with the same unsettling expression he has now.

Cathy feels a sudden foreboding that Brian should not leave the house as he heads out to meet Susan after school.

Dave argues the group should untie Mr. Griffin and leave immediately; Mark refuses and insists Mr. Griffin must beg first.

Mark reveals to the group that his own father died in a house fire, using it to minimize their guilt over Mr. Griffin.

Cathy recognizes Mark's name during her confrontation with Susan and connects him to a plagiarism scandal in Mr. Griffin's class.

Mark steals Mr. Griffin's wallet from the body while Jeff begins digging a grave at the waterfall.

Dave closes Mr. Griffin's eyes, drapes a jacket over his face, and attempts to say a prayer before the burial.

Dave pries Mr. Griffin's college ring from his finger before the body is buried, drawn by its connection to his father's university.

Mark confronts Betsy about the speeding ticket she concealed from the group, warning that it puts everyone's alibi at risk.

Dave and Susan find the ring gone from his drawer, and Susan accidentally reveals to his grandmother that the ring has a stone.

Susan calls Mark to report the ring is missing from Dave's drawer, and Mark calmly tells her not to worry.

Susan directly accuses Mark of killing Dave's grandmother; Mark denies it and turns the accusation back on her.

Jeff refuses to tie Susan up as Mark commands, saying he will not do to Susan what they did to Mr. Griffin.

Mark tells Susan he deliberately burned down his Denver house to kill his father, who had threatened to have him sent away.

Susan finds a note from Cathy Griffin delivering Mr. Griffin's final written evaluation, in which he praises Susan's promising talent.

From the earliest warning signs — Jeff's memory of Mark burning a cat and Cathy's unexplained foreboding — the novel seeds its most crucial turning points long before the crime is committed. The single most consequential decision comes when Dave tries to free Mr. Griffin early but Mark refuses, sealing the teacher's fate. Hidden acts during the burial, including Mark stealing the wallet and Dave taking the ring, set off a chain of events that no one anticipates. As the cover-up unravels, the stolen ring leads Mark to murder Dave's grandmother, finally stripping away any doubt about his true nature. Susan's direct accusation of Mark forces both of them into a final, desperate confrontation inside her own home. The revelation that Mark killed his own father — and Cathy's timely rescue of Susan — brings the story to its emotional and moral resolution.