In this episode, Veronica helps Cindy "Mac" Mackenzie find and reconnect with her birth parents and siblings. Meanwhile, Keith is temporarily reassigned to the sheriff's department in order to help with a case involving a serial killer.
One morning, Veronica talks to Keith about an old case involving a serial killer, the E-String Strangler, who has made a reappearance. Wallacealso complains to her about the panic that's been going throughout the town because of the killer. Meanwhile, another student, Jackson, asks Veronica to track his parents. Sheriff Don Lamb and the mayor of the town meet with Keith. After the conversation, Keith comes out and tells Veronica gleefully that he's going to start working at the sheriff's department again. But Keith says that it is only temporary, but he is getting paid his regular salary. Later, another student asks Veronica for help with her parents. Sheriff Lamb and Keith explain the case to other police officers, but they have conflicting styles. Meanwhile, Veronica's parent-seeking business takes off, and Mac notices. Mac comes up with an idea to double their fees, so they will eventually have enough money for retirement savings. Veronica says she'll think about it. Veronica also finds that Mac's parents once sued the Neptune hospital for 1 million dollars. Veronica finds that Mac was switched at birth. Keith and Sheriff Lamb visit a record shop, but they find nothing. Veronica visits Mac's house, and she shows Veronica her room. Veronica tells her that she was switched at birth with a popular cheerleader, Madison Sinclair.
Keith and Sheriff Lamb talk to a suspect, who leads them to a man called "The Worm" (Aaron Paul), who responds hesitantly. Both of them think he is the killer given that he had a guitar. Veronica, Mac, and Wallace invite themselves over and crash Madison Sinclair's 09er party. Mac looks around the house and meets her biological sister, with whom she connects. The new police officer tells Keith and Sheriff Lamb that "The Worm's" guitar strings match the strings which were used to strangle the victims. Veronica bribes the new police officer and steals the Lilly Kane murder files with the help of Weevil. Veronica listens to the tapes she stole, and doesn't find anything until she hears a suspicious synthesized voice. Keith and Sheriff Lamb talk to "The Worm", who sexually abused both the victims. "The Worm" demands a lawyer. Veronica contacts Mac about the synthesized voice and tells her that there was a reason why she was not switched back to the right parents.
Mac goes to Madison Sinclair's house under the guise of looking for her purse. A woman runs screaming into the Sheriff's department reporting a missing daughter. Keith tracks Veronica out of fear for her. He finds Veronica and tells her about the new missing girl. Keith breaks into the record shop he earlier entered with the man who previously mocked him. Mac tells Veronica that she's decoded and the message. Veronica eventually says that she knows whose voice it is. Mac sees her biological mom waiting in the car outside with tears in her eyes. She puts her hand on the window and touches her mom's hand before her mom drives away. It turns out that the voice is Clarence Wiedman's voice, the man who took unauthorized photos of her. Veronica takes pictures of him and his family and sends them to him as revenge.
- Veronica takes advantage of new Deputy Leo D'Amato to steal the Lilly Kane hotline CD and has Mac demodulate the voice, revealing that it was Clarence Weidman who gave the anonymous tip.
Many cultural references are made in the episode:
- Madison's parents send her a string quartet which plays "Birthday" for her birthday.
- Veronica mentions Rod Serling.
- Sheriff Lamb compares the E-String Strangler case to the Hillside Strangler murders, a real life incident in which two men strangled tens of girls to death.
- Veronica references the Internet Movie Database.
- Keith is surprised that Sheriff Lamb has never seen This is Spinal Tap.
- Mac and Veronica mention Fievel Mousekewitz, a character in the 1986 animated film An American Tail.
- Mac's blood sister is reading The Westing Game.
- Mac derides Madison's art appreciation by saying that she wouldn't recognize Claude Monet's Water Lilies unless Revlon created and named a nail polish after it.
- Keith and Sheriff Lamb decide whether or not to play "Good cop/bad cop" with their suspect.
- Mac's adoptive father references the 2000 memoir A Heartbreaking Work of Staggering Genius.
- Kristen Bell as Veronica Mars
- Percy Daggs III as Wallace Fennel
- Teddy Dunn as Duncan Kane
- Jason Dohring as Logan Echolls
- Francis Capra as Eli "Weevil" Navarro
- Enrico Colantoni as Keith Mars
- Tina Majorino as Cindy "Mac" Mackenzie
- Michael Muhney as Don Lamb
- Max Greenfield as Leo D'Amato
- Aaron Paul as Eddie LaRoche
- Steve Monroe as Gabe
- Christopher B. Duncan as Clarence Wiedman
- Carlie Westerman as Lauren Sinclair
- "Brilliant Sky" - Saybia
- "Fireflies" - Amy Cook
- "The Way You Are" - 46bliss
- This episode was originally supposed to air before "An Echolls Family Christmas".
- Despite being credited, Jason Dohring (Logan Echolls) and Teddy Dunn (Duncan Kane) do not appear in this episode.
- Veronica: Can I get anybody anything? Water? Coffee? [to Lamb] A banana?
- Lamb: Is your daddy here, or is he busy peeking in people's windows?
- Veronica: You stop dressing up like Little Bo Peep, he'll stop peeking.
- Madison: What are you doing here?
- Wallace: I came to celebrate your birth, but these two just wanna hook up.
- Weevil: Well then, you leave the sheriff a note: he shouldn't expect Eli Navarro, Esquire's vote this year!
- Veronica: [voiceover] Same old story. Girl uses boy, girl falls for boy, boy saves girl's dad's life, girl gets what she deserves.
- Jackson Douglas: I hear you do detective stuff for people.
- Veronica: I do favors for friends.
- Jackson Douglas: I can pay.
- Veronica: Sit down, friend.
- Jackson Douglas: I don't care what people say about you, Veronica. You rock!
- Veronica: Yes, I do. I also take cash.
- Keith: [in a guitar store] Hello Cleveland!
- When Mac comes across Lauren Sinclair in the library, Lauren says she is reading The Westing Game. This is a young adult novel by Ellen Raskin, originally published by Dutton in 1978. The plot revolves around a teenage girl who solves a complicated murder mystery involving a large group of possible suspects -- just as Veronica does over the course of the first season.
- The title Silence of the Lamb is a reference to film The Silence of the Lambs starring Anthony Hopkins as Hannibal Lecter.
- This episode marks the first appearance of Leo D'Amato.
- When Cindy's mom brings Mac and Veronica some snacks, she remarks that she isn't sure if Veronica was "a normal eater or one of those freakball vegans, like Cindy." Veronica replies that she is "more normal than freakball." Kristen Bell, who plays Veronica Mars, is a vegan in real life.
- When Veronica brings Leo the food to give to her dad, Leo's computer monitor shows a "Low Battery Warning" from the Mac OS X operating system. There is no laptop in the scene. Desktop computers don't get low battery warnings.
- When the mother of the newest girl who is missing comes to make the complaint, Leo is the person at the front desk who takes the complaint. In the next scene, Keith interrupts Leo's band's practice to find Veronica. Leo is there, and has no idea that another girl is missing.
- The employee at the music shop's guitar has sound coming out of it, and not the amplifier which must be at least ten feet away.