A new girl from Toronto, Laurel, arrives at school, causing disruption among the friends. Problems at home cause Mark to be suspended from school and Travis to disappear.
Mark and Jen have been together six months, and she plans on having sex with him. When Mark and Laurel are spotted hanging out, Anika and Erin spread rumors about them. Laurel apologizes to Jen and confronts Anika and Erin, making them hate her even more.
Mark misleads Jen while falling for Laurel. Scott meets the girl of his dreams. Cat tells Jen that Mark has been emailing and talking with Laurel behind her back. Erin pines over Chris, who's more interested in Anika. Jen reads Mark and Laurel's emails.
Things get steamy when Mark poses for Laurel's photo shoot. Erin attempts to dissuade Chris's interest in Anika. Chris wagers against Gil that Anika will have sex with him. Jen becomes increasingly more suspicious of Mark and Laurel and for good reason.
Laurel tells Mark she can't be with him when he's still with Jen. Jen contemplates having sex with Mark to keep from losing him. When Anika hears the rumours going around about her, Erin blames Laurel. Mark tries to end things with Jen.
Mark and Jen deal with the aftermath of their night together. Chris pursues Anika in order to fulfill his bet with Gil. Mark tries to come to grips with his feelings for Jen. A hurt Jen "subtly" mentions her budding sex life to Laurel.
Anika completely blows off Chris. Shannon attempts to mend fences with Jen. Erin tells Chris that Anika is a virgin. Laurel ends things with Mark for good. When Mark learns his dad has cheated on his mom and left, he tries to solidify things with Jen.
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 Shannon mentions something to Craig. Chris apologizes to Anika, but his bet with Gil is still on.
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.
Anika and Chris go out on a date. Scott buys Brenda underwear. Mark tries to make up with Jen. Mark, Cat and Travis try to cope with their parents' impending divorce. Chris tells Erin to back off when she continues to come on to him.
Jen calls things off with Mark, Erin deals with the consequences of hooking up with Gil, the war rages on between Anika and Chris, Derek is arrested, Scott confronts Brenda about their relationship, and Mark reconnects with Laurel.
