Cat and Mark try to find their missing little brother. Scott attempts to ask out Laurel. Anika spreads rumours about Laurel. Mark and Laurel meet for the first time. Jen finds Travis, Mark's little brother sleeping in her car. Gil accidently insults Chris. Erin spies Mark and Laurel having coffee together. Cat busts Mark on his email from Laurel.

After their illicit kiss, Laurel tells Mark she can't be with him when he's still with Jen. Mark tells Laurel he will break up with Jen. While feeling she may be losing Mark, Jen contemplates having sex with him in order to keep him. Scott throws an Equinox party. Craig leads a one-man protest at the Cafe Java but when he chains himself to the table and insults Maggie, she leaves him there overnight. When Anika hears the ""torrid affair"" rumours going around about her, Erin tells her it was Laurel who started them (when really it was a jealous Erin). Laurel and Jen work uncomfortably on a school project together. Mark goes over to Jen's to end things with her but they end up having sex. When Mark falls asleep, Jen is left looking very unsure of herself.

Brenda and Scott go on their first real date...to her church youth group. Mark and Jen's sex life becomes the talk of the school when Laurel mistakenly mentions something to Craig, while his sister Erin is nearby. Craig tells Shannon about his endangered frog project. Chris apologizes to Anika, who softens towards him, but is completely unaware of his bet with Gil, unlike Erin who reveals to Chris that she knows. Mark attempts to mend his friendship with Laurel but is shot down. Mark and Jen try to determine who told about their love life and Jen falsely accuses Laurel when it was really Shannon, Jen's best friend.

Erin and Chris go out on a date, but to Erin's disappointment, all Chris really wants is Anika. Laurel tells Jen about her and Mark which causes Jen and Mark to argue about Laurel. Scott asks out Brenda. Craig and Laurel work on a Save the Frogs campaign.