Marissa and Ryan try to start over as friends, but it's not as easy as they had hoped. As Theresa (recurring guest star Navi Rawat), Ryan's ex-girlfriend from Chino, begins spending more time in Newport, Ryan discovers that she hasn't been honest about why she's there. Seth believes his relationship with Summer is great, but when she refuses to acknowledge him at school, he feels he has to teach her a lesson. Meanwhile, Sandy finds himself embroiled in another mess created by Caleb (recurring guest star Alan Dale). And Jimmy begins to suspect something is going on between Julie and Luke.