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.

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.

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.

Following an emotional reunion with her mother, Veronica is hired to track down Neptune High's beloved mascot, Polly the Parrot, which was apparently kidnapped by a rival school on the eve of a big basketball game.

Meanwhile, with her suspicions about the Kane family rekindled, Veronica attempts to gain access to her father's original interrogation tapes. Later, Veronica's relationship with Deputy Leo heats up, as does Meg's relationship with Duncan.

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.

While helping her classmate Mandy search for her missing Jack Russell terrier, Veronica stumbles onto a bigger mystery, which affects pets all over Neptune.

Meanwhile, tensions mount in the Echolls family as Trina tries to convince the now-retired Aaron to take a part in her new boyfriend's independent movie. Later, Weevil is arrested for breaking into the Kane residence and taking something from Lilly's room.

After the summer fireworks caused by a dangerous confrontation with Lilly Kane's murderer and a surprising visitor at her door, Veronica attempts to settle into "normal" life, complete with a new after-school job and a return to the popular fold at Neptune High, but she gets pulled back into the investigation business when Wallace is kicked off the basketball team for testing positive for drugs.Meanwhile, Keith sits down with reporter Julie Chen to discuss his new book on the Lilly Kane murder, "Big Murder, Small Town." Later, after seeing his father arrested for murder and being charged and tried for murder himself, Logan seeks refuge from the paparazzi and relaxes poolside at the Casablancas mansion with buddies Dick and "Beaver" and their sexy stepmother Kendall.

Called to jury duty over Christmas break, Veronica must sit on a difficult, polarizing case against a pair of affluent 09'er defendants accused of assaulting a young Hispanic woman. Meanwhile, when the Aaron Echolls/Lilly Kane sex tapes go missing from th

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

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.

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.

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.

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.

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.