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 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.

Veronica and Keith's client, Daniel Maloof, makes a shocking confession. Sheriff Langdon closes in on her top suspect. Veronica and Matty join forces, just as the whole investigation is flipped on its head.

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 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.

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.

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.