In the shocking, action-packed season finale, a determined Veronica must betray someone she cares deeply about in order to solve the season-long mystery of who murdered her best friend Lilly Kane, but what she discovers puts her life in serious danger. Meanwhile, on the eve of a reception for the Governor of Calif., Jake Kane asks Duncan if he really wants to know what happened on the night Lilly died. Later, Keith awaits the results of a paternity test.

After discovering the true perpetrator of the bus crash, Veronica is desperate to warn others before it's too late. However, she inadvertently puts herself and her loved ones at risk in the process. Meanwhile, Keith tracks down Woody in hiding, Wallace leaves for Paris to be with Jackie, and Weevil again runs into trouble with the law.

After the campus rapist anonymously announces the location of his next rape, Veronica hires her friends to help her track him down, but is shocked when she discovers the rapist's identity. Meanwhile, Logan makes a drastic decision about his future with Veronica, and Dean O'Dell hires Keith to prove that his wife is unfaithful.

Determined to get to the truth behind who drugged and assaulted her at a party the year before, Veronica questions her friends and many rivals about the chain of events that night at Shelley Pomroy's house. Meanwhile, when one of Veronica and Wallace's stunts affects her job at Kane Software, Alicia confronts Keith about his daughter's behavior. Later, in an attempt to get closer to his son, Aaron throws a birthday party for Logan that inadvertently surprises everyone.

When Veronica discovers Timothy Foyle breaking into Mars Investigations, she uses his help to track down Dean O'Dell's true killer. Meanwhile, Logan and Parker's relationship takes an unexpected turn, and acting Sheriff Mars brings another murderer to justice.

As the end of the first semester at Hearst College draws to an end, the election for sheriff in Neptune comes to a close and Veronica and Piz discuss the effect a summer apart will have on their relationship.

When Duncan disappears with Meg's baby, Lamb must work with two FBI agents to extract as much information as possible from an uncooperative Veronica. Meanwhile, Wallace reveals the real reason he returned to Neptune, and Weevil and Logan make a breakthrough in their hunt for the rogue gang member.

When one of Neptune High's haughtier students brings a sexual harassment suit against a favorite teacher, Veronica finds herself pitted against her father when the girl's parents hire Keith to help in their case. Meanwhile, with the tabloids claiming his mom is still alive, Logan turns to Veronica to help him track down the truth. Later, Veronica discovers more unsettling information about Duncan's hidden medical condition.

A series of fire drills leads Veronica to discover that Neptune High has been receiving bomb threats, so she enlists Wallace and Mac's help to investigate classmates who could pose a serious threat to the school, including new student Ben. Meanwhile, Keith stuns Veronica with the news of who he's been secretly dating. Later, Duncan confronts Veronica about her ongoing investigation into his sister's death.

When a classmate's boyfriend threatens to post a humiliating video of the girl online if she dumps him, Veronica helps her concoct a scheme to ensure "mutually assured destruction" if he doesn't allow the relationship to end peacefully. Meanwhile, Keith begins to search for Duncan after his parents post a huge reward for information on his whereabouts. Later, as her secret new relationship heats up, Veronica learns a disturbing new fact about the night that she was drugged and assaulted.

Weevil asks Veronica to clear his name after he's arrested for selling fake debit cards to Hearst students, claiming he's being framed because of his criminal background.

When Veronica is released from jail, she is contacted by Josh Barry who is desperate to prove his innocence in his father's murder. Meanwhile, Keith gets bittersweet news from the county commissioner, and Logan helps Mac and Parker on a scavenger hunt.

Veronica takes the stand in Aaron Echolls's murder trial, and is distracted during final exams while waiting for the verdict. Meanwhile, Keith takes new evidence about the mayor to Lamb, and Weevil asks Mac and Cassidy for help to pass algebra.

Veronica uncovers information that her fellow outcast Mac was switched at birth with a more affluent student, causing Veronica to examine her own questions about whom her real father may be. Meanwhile, a serial killer has resurfaced in Neptune forcing Sheriff Lamb to forge a reluctant, tense partnership with Keith. Later, Veronica flirts with a handsome young rookie at the sheriff's department to obtain more information on Lilly's murder.

To help restore a cheerleader's ruined reputation, Veronica turns to funky computer geek Mac to find the hacker responsible for leaking the embarrassing, private results of a popular online "purity test" to all of Neptune High. Meanwhile, Keith helps Wallace and his mom with an unruly tenant in their building. Later, to get answers about Lilly's murder, Veronica attempts to visit Lilly's confessed, condemned killer Abel Koontz in prison.

Veronica investigates who at school is doing everything possible to distract Sabrina from studying and wreck her grades in an obvious attempt to sabotage her chances at becoming valedictorian. Meanwhile, an unsavory, rival private investigator makes Keith a business offer. Later, Veronica pursues a risky lead that could discredit Abel Koontz's confession, as Logan stumbles onto her detailed files on everyone connected to Lilly's murder.

Keith takes on a second concurrent murder case when the head of the Hearst basketball team turns up dead and his son is the prime suspect. Meanwhile, a depressed Logan refuses to leave his hotel room and ends up babysitting Dick's girlfriend's little sister for days.

Gia enlists Veronica's help to find out who is stalking her, and Clemmons cancels the senior prom.

Veronica surprisingly finds herself working as a "love detective" when she's asked to track down her friend Meg's secret admirer and a Russian bride's estranged fiancé. Meanwhile, after discovering that one of Lynn Echolls' credit cards is in use, Veronica and Logan go to a Los Angeles hotel in hopes of finding her or a clue.

When Weevil's poker winnings go missing after a game at Logan's place, Veronica questions each player to piece together the evening's events and catch the thief. Meanwhile, on the eve of the Echolls' annual Christmas party extravaganza, Keith is hired by Lynn Echolls to track down one of her husband Aaron's potential stalkers.

When the profits from the Neptune High Winter Carnival go missing, Veronica finds herself defending Jackie from the condemning teachers and students. Meanwhile, Keith meets with her father, Terrence Cook, after he is accused of playing a role in the bus crash, and Logan initiates a new relationship while Beaver continues an old one.

When a family accuses Veronica of providing a fake ID to their son, now in an alcohol-induced coma, and files suit, the search to find who's really responsible leads Veronica to a clandestine, exclusive organization operating on Neptune High's campus with a possible connection to Duncan. Meanwhile, Aaron Echolls hires Keith to find out who's been supplying pictures to the tabloids that have humiliated his wife Lynn. Later, Veronica bugs Ms. James' office to eavesdrop on grief counseling sessions, and learns some surprising information about her friends.

Wallace's new girlfriend Jane enlists Veronica's help when her older sister Heidi appears to be a "runaway bride," but the clues suggest something possibly more disturbing happened on the way to the altar. Meanwhile, Keith and Veronica decide that they have no choice but to go to Sheriff Lamb with the evidence they've uncovered about the bus crash. Later, Kendall has a tempting offer for Aaron Echolls.

Wallace's hopes of escaping his trouble in Chicago are dashed when Rashard's uncle accuses him in the press of a hit and run. Meanwhile, Weevil has Veronica bug a church confessional to smoke out the traitor in his bike gang.

Veronica doesn't believe the evidence adds up against Weevil, who has confessed to stealing credit card applications from Logan's family, and launches an investigation to help her new ally. Meanwhile, after joining Ms. Mallory Dent's newspaper class, Veronica clashes with socialite Caitlin Ford, Logan's bombshell girlfriend, but is intrigued by the attention shown to her by another wealthy student, Troy Vandegraff, a friend of ex-boyfriend Duncan. Later, Veronica learns that Lilly got a ticket driving her car on the day she died -- two hours after her supposed time of death.

Veronica discovers Keith has been hiding something scary from her. The real reason for Penn’s latest theory on the bomber comes to light. Veronica loses confidence in new friend, Nicole, owner of Comrade Quacks.

Veronica begins having dreams involving the dead students from the bus crash, who drop clues along the way. Meanwhile, Logan and Wallace become unlikely lab partners in Mr. Wu's class, and Keith helps Clemmons expose a doctor's scam.

With only a commonplace name, an old address and dim memories as leads, Veronica and Wallace attempt to help classmate Justin Smith find his father John, who disappeared 10 years earlier. Meanwhile, as Veronica faces some complicated feelings towards ex-boyfriend Duncan and new romantic interest Troy, guidance counselor Rebecca James calls Keith to the school to discuss the recent, dramatic changes in his daughter's life. Later, Duncan struggles with ways to cope with his sister's death as the anniversary of her murder approaches.

Panic spreads through Neptune when a bomb goes off during spring break. Veronica and Keith are hired by the wealthy family of one victim injured in the bombing to find out who is responsible.

As Veronica learns more about Nicole's past, her suspicion deepens. A frantic phone call from Paris leads to a search for Matty. Veronica unwittingly does legwork for Leo.

After being hired by hip-hop heavyweight Percy "Bone" Hamilton to find his kidnapped daughter, Veronica and Keith look to the music mogul's long list of enemies, family members and the girl's Neptune High social circle for clues on her whereabouts. Meanwhile, following Lynn Echolls' apparent suicide, Logan cynically endures his father Aaron's effusive displays of grief as they prepare for her memorial ceremony.

Veronica's detective prowess is again used on campus when Piz's football friend loses the team playbook and Veronica must get it back before the game. The Dean threatens to expel Veronica if she doesn't reveal the source of her newspaper article. Meanwhile, Keith hires Weevil to work in the office, and Logan's antics catch up with him.

Convinced the bomber is still at large, Veronica visits Chino to learn more about Clyde and Big Dick. Mayor Dobbins’ request for help from the FBI brings an old flame to Neptune. Veronica confronts her mugger.

Veronica and Keith follow a new lead, and discover another victim. Matty follows her own instincts, landing herself dangerously close to a killer. Veronica has a tragic epiphany as the clock is ticking.

Logan gets a big surprise when he hires Veronica to find the source of his missing inheritance, which escalates from weird to worse. Meanwhile, Dick's fraternity asks Veronica to prove their innocence in the campus rapes, and Keith helps an old acquaintance prove her husband is cheating.

Veronica and Keith launch their investigation. Their involvement puts Police Chief Langdon on edge. Penn goes public with his theory on who the bomber is. Meanwhile, local teen Matty Ross begins her own search for her father’s killer.

Desmond Fellows, a singer/musician from a 1990's pop band arrives on the Hearst campus to perform at a benefit concert to keep the station from going out of business. Piz gets the job of his dreams when he is put in charge of hosting Fellows around campus and on air. However his dreams start to dissolve as things don't go quite how he imagined, in more ways then one. Keith is excited about the upcoming Sheriff's race unopposed until he unwittingly helps promote an unlikely candidate who throws his hat into the ring.

When a private website for Neptune High's gay students is hacked, and the members blackmailed, Veronica finds it difficult to track down the culprit when the victims want to remain anonymous. Meanwhile, Hannah finds out Logan's true intentions, and Keith believes he has found an alibi for Terrence.

The campus newspaper hires Veronica for an undercover expose on the Zeta Theta sorority sisters during rush week to investigate Parker’s rape. Veronica begins to realize though that not everything is as it appears in the sorority house. Logan and Wallace take part in a challenging Sociology class role-playing experiment as prisoner and prison guard, and Keith treks through the desert after escaping from the scene of a crime.

With Keith acting-sheriff, Veronica goes solo on a case involving a local restaurant whose owners are the targets of hate crimes. Meanwhile, Keith is disturbed by the lack of professionalism in his deputies when he orders them to fine bars serving alcohol to underage patrons. Logan throws a birthday party for Parker, and Piz decides to finally confront Veronica about his feelings.

Veronica becomes suspicious when a young pregnant woman who lives in their apartment complex with her volatile boyfriend suddenly disappears; fearing the worst, Keith steps in to help his daughter investigate this case for the girl's estranged parents. Meanwhile, Logan and Weevil get thrown into detention together after arguing with a teacher, leading the rivals to discover some surprising things in common. Later, while working on an alumni photo project in her journalism class, Veronica is shocked to discover in the '79 yearbook that her mother and Jake Kane were high-school sweethearts.

Deciding to give Jackie the benefit of the doubt since she's dating Wallace, Veronica tries to help Jackie determine who stole her credit card, leading Veronica to appear on a psychic's community access show to pursue a lead. Meanwhile, Wallace confronts his mother Alicia about who his real father is. Later, Veronica learns of a voice mail recording from one of the students that died, made at the moment the bus crash.

The wealthy parents of a Neptune High senior hire Keith and Veronica to investigate a cult-like group and its charismatic leader after their son Casey moves out to live on the collective farm. Meanwhile, Veronica attempts to get to the bottom of Abel Koontz' claim that her real father is Jake Kane.

While accompanying Wallace to Hearst College, she runs into her ex, Troy Vandergraff, who enlists her help when he is accused of date rape. Meanwhile, Keith helps Cliff with a personal problem involving a prostitute, and Logan makes a decision regarding his relationship with Hannah.