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.

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.

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.

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 tragedy strikes Neptune, Calif. and the local sheriff rushes to judgment, an emotional Veronica attempts to help a grieving family member rule out suicide as a contributing cause in the calamity. Meanwhile, Wallace offers to help transfer student Jackie Cook, the fiery, flirty daughter of professional baseball player Terrence Cook, track down the person who damaged her car in the school lot. Later, mayoral candidate Woody Goodman asks Keith to consider running for sheriff.

Veronica and Duncan discover that the still-comatose Meg had been babysitting an abused child, leading Veronica to take on an unfamiliar role as a babysitter to determine the kid's identity. Meanwhile, Kendall continues her affair with Logan as her stepso

After Veronica gets busted for breaking into the school office and ordered in detention to reorganize the school's files, she stumbles on her mother's permanent record and learns that she was suspended for reasons that cause Veronica to further question e

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.

Veronica and Mac help campus researchers locate a missing monkey who was allegedly stolen by animal rights activists. Meanwhile, Keith is approached by Mindy O'Dell, who claims her husband's death was murder, not suicide. And in the aftermath of his breakup with Veronica, Logan turns to Dick for advice.

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.