Seventeen-year-old Rue returns home from rehab with no plans to stay clean. She meets Jules, who's new in town, at a party at McKay's house. Nate gets in McKay's head when McKay takes an interest in Cassie. Nate and Maddy, who have broken up once again, attempt to make each other jealous. Meanwhile, Kat is pressured to lose something big.

On the first day of school, Rue's excited about her new friend, Jules, but struggles to put the past behind her and gets into trouble at Fezco's. Nate becomes obsessed with Maddy's hookup, Tyler, while trying to get back together with Maddy. Kat finds out that a video of her has surfaced online. McKay takes the stress of college out on Cassie.

Kat decides to try camming and has her first session. Jules starts falling for a boy online and asks Rue to help her take some nudes. Maddy finds something odd on Nate's phone. Cassie and McKay spend the weekend at his school and go to a party at the frat he's rushing. Rue is confronted about her lies at NA.

Rue tries to get clean for Jules and chaperones Gia at the carnival. Jules encounters Cal with his family. Cassie and Maddy, annoyed at their boyfriends, decide to do molly together. Kat hangs out with Ethan until she misreads a situation. Nate reveals who he really is.

In the aftermath of the carnival, Maddy and Nate are forced to deal with a police investigation. Jules begins to feel pressured by her role in Rue's sobriety. Kat ignores a confused Ethan and embraces her new lifestyle. Cassie ries to distance herself from Daniel and focus on her relationship with McKay. Cal worries about how his actions have affected his sons.

On Halloween, Rue worries about her reliance on Jules, while Jules starts exhibiting concerning behavior. McKay questions his future in football. After a weird night with McKay, Cassie spends time with Daniel. Business is booming for Kat as she continues to push Ethan away. Nate comes up with a plan to get his life back on track.

Rue gets depressed and watches 22 straight episodes of a British reality show.​ Jules goes to visit an old friend. Cassie looks for advice in the aftermath of Halloween night.

In the Season One Finale, it's the winter formal at East Highland.

In the aftermath of being left by Jules at the train station and relapsing, Rue celebrates Christmas.

Over the Christmas holiday, Jules reflects on the year.