While trying to navigate the everyday drama of high school, the smart, fearless, 17-year-old Veronica Mars also moonlights as an apprentice private investigator out to solve her wealthy town of Neptune's toughest mysteries. After coming to the aid of the new kid, sophomore Wallace Fennel, who's been duct-taped to the school's flagpole, Veronica ends up incurring the wrath of the thugs who put him there, Eli "Weevil" Navarro and his P.C.H. Biker Boyz. To get Weevil and his gang off her and Wallace's case, Veronica devises an intricate plan that helps some of Weevil's cronies avoid trouble with the law.

Meanwhile, defying her father, Keith Mars, the disgraced former sheriff turned private eye, Veronica pursues a late-night case of adultery against billionaire Jake Kane, only to make an unsettling discovery about her mother, who abandoned Veronica and Keith a year ago.

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.

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.

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.

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.

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.

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.

With Aaron Echolls facing trial for Lilly's murder, the previously accused Abel Koontz appears to enlist Veronica's help in finding his missing daughter Amelia, leading to a confrontation with Kane Software's head of security. Meanwhile, Logan is arrested

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.

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.

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.

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.

What promises to be a simple case of finding out who ran over a classmate's dog turns into a startling revelation when new secrets about the bus crash come pouring out and Veronica finds herself again revisiting Lilly's murder case. Meanwhile, Wallace and Jackie try to turn their relationship around the corner, and the PCHers turn to Weevil for protection from the Fitzpatricks.

When the illegal casino Veronica frequents is robbed, she must track down the thief to recover the necklace Lilly gave her years before. Meanwhile, Dean O'Dell's stepson is dying of cancer and needs Keith to track down his biological father for a transplant (with Cliff's help), and Wallace fears he may flunk out of his most important class.

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.

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.

Apollo, a Hearst student who suffered hardships as a child soldier in Africa, appears on Piz's radio show, prompting a man to come forth claiming to be his father. But Veronica's investigation unearths some surprises. Meanwhile, Neptune is faced with a crime spree that could spell trouble for Keith's campaign, and Logan finds himself in a difficult situation when Parker wants to spend to summer with him. Veronica awaits the results of her FBI exam.

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.

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 debates coming clean to Nicole. Veronica’s fidelity is tested. Veronica and Keith discover they aren’t the only ones who believe they’ve found the bomber. A surprising potential client tries to hire Mars Investigations.

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.