Ms. Glass wants all the students to write down where did they go for Spring Break and how many they slept with, so, in her own words, she can judge them. Most of the gang say they went to Cancun, and Harrison writes that he went to Yemen as his nose starts to bleed. Ms. Glass deduces he has been infected with the Rift Valley fever that is contaminating everyone in Yemen. Just as Sam was trying to talk to him by his locker, they are both isolated from the rest of the people and the school is shut down in quarantine. During Chemistry, Mary Cherry receives a call in her cell phone from someone who knows what she really did for Spring Break - a low-budget soft porn scary movie - and she has to run for her life as she is chased to be killed. Meanwhile, Lily tells April what they really did for SB. They intended to go to Cancun, but they all stayed in LA and had SB in different ways. Nicole is elected to attract the killer, but since she's not a virgin, and only virgins get chased by killers in scary movies, they fail. When the gang realizes they've all lied to each other about the SB, they decide to reveal the truth. Among romantic dinners and break ups, the most shocking revelation comes from Brooke and Harrison, who have slept together! Harrison and Sam make up and kiss, just when George walks in the nurse's office. Suddenly, the real Dr. Salk appears and the killer is revealed to be the travel agent to their trip to Cancun, who was trying to get back at the kids for ruining her bonus.