Flashback to the '80s.

Haley, Quinn and Taylor receive a surprise visit from their mom Lydia who tells them that she has incurable pancreatic cancer and that she is not seeking any further treatment. Quinn takes the news very hard but Clay is there to support her. Meanwhile, Alex sets her sights on Alexander as Brooke and Julian try to get their old relationship back on track, and Millicent finds herself struggling with temptation.

Haley and Quinn refuse to accept that their mom Lydia will not fight her pancreatic cancer and after some convincing manages to persuade her mother to get a second opinion with Nathan's doctor but the results don't bring any change. Because she told Jamie that she won't be alive for Christmas he organizes for her to have Christmas now with the family. Meanwhile, Brooke and Julian's relationship moves up a notch but comes crashing down spectacularly when Brooke finds Alex in his bed but is it what it seems? Elsewhere, Grubbs puts Miranda through hoops before he allows her to produce his album with her and Owen Morello comes back into Millie's life much to Mouth's displeasure.

In getting back at Julian for sleeping with Alex, Brooke messes with the costumes for the shoot and generally does her best to wound Julian but it takes comments from Alex to get her thrown off the set after she punches Alex in the face. Only later does she discover that it was Alexander that Alex slept with as she switched rooms with Julian. She tells Victoria who is furious and it later transpires that her mystery lover is Alexander. Meanwhile, Lydia takes ill from her cancer and is hospitalized and reaches out to the daughter Taylor but it is Quinn who manages to get her to come before she dies. Elsewhere, Clay tells Katie he won't be representing her but it doesn't put off Katie and she finds out that he was married to Sara so she transforms herself to look like her. Lauren and Mouth nearly get it together only for Skills to come back to Tree Hill.

Quinn's gallery opens with Clay very supportive unaware that he is being stalked by Sara lookalike Katie until she makes her presence known and Clay shows Quinn how alike Katie is to Sara. Josh's sex tape with Alex is emailed to Julian's father with a demand for $1,000,000 putting the film in jeopardy. Miranda finds out she is being deported thus putting a spanner in the works with Grubbs's recording but Grubbs finds a way around it by proposing to her. Lauren tells Skills that she has fallen for someone else but he is unaware it is his best friend Mouth until he sees a photo of them at the gallery where he promptly punches Mouth. Meanwhile, Victoria's affair with Alexander is exposed in more than one way. Elsewhere, Nathan and Jamie spend a guys evening together & later he asks Haley if she'd be ready to try for another baby. She tells him she took a pregnancy test and it was negative but is she telling him the whole story?

As the gang returns from Utah, Brooke and Julian are engaged, Haley learns that she is pregnant, Nathan must leave for training camp, and Clay and Quinn are assaulted and shot by Katie.

Clay and Quinn discover they've been shot, and as they fight to live, Nathan and Haley struggle with the situation. Meanwhile, Julian tries to preoccupy Jamie, and Brooke's legal troubles mount.

As Brooke deals with the mounting financial troubles at Clothes Over Bro's, Nathan and Haley come to a conclusion regarding Nathan's career. Meanwhile, Julian begins a new film project, while Alex and Chase spend the afternoon together.

As Halloween approaches in Tree Hill, Brooke and Julian get an unexpected visitor, and Nathan begins a new career. Meanwhile, Clay and Quinn struggle with life back at the beach house, and Haley and Mia host an open mic night at Tric.

Clay finally gets some hand muscle control back. As he predicted, Nathan had no reason to be gloomy about his first contract, football talent Troy, which is signed to all parties' satisfaction. Julian and Brooke stand up to his mother, who has to back down on the fancy wedding plans but relapses into drinking. After some occupational therapy for Mouth and himself, Chase handles his Alex-Mia-dilemma. In Nathan's absence, Jamie finds it even harder to face the peril of peer ridicule for getting braces, which Haley only compounds by wearing a 'commiserative' eye-patch.

After a wild night out on the town for her bachelorette party, Brooke and the girls try to piece together the night before amidst the wreckage of the day after.