After Lucas and Keith learn that Dan had a heart attack and is still in the hospital, they decide it is best for them to return to Tree Hill. When Deb learns about Haley and Nathan's marriage, she grows hostile. Meanwhile, angry that Lucas left Tree Hill without saying goodbye, Peyton and Brooke try to mend their friendship.

With the assistance of Peyton and Brooke, Lucas throws Nathan and Haley a wedding reception. Although Haley's parents support the marriage, Deb has a difficult time accepting it. Meanwhile, Dan's recent heart attack causes him to try and mend his relationships with Deb and Lucas.

Brooke and Julian try to find a balance between their personal lives and work as the movie shoot begins. Nathan and Haley receive a surprise visit, and Clay supports Quinn as she faces some unexpected news., Alex sets her sights on Alexander, and Millicent finds herself struggling with temptation.

Nathan tries to help Haley and Jamie confront Lydia's seemingly hopeless situation, while Brooke and Julian navigate their volatile relationship in the midst of a hectic movie shoot. Meanwhile, Clay and Quinn spend some time apart, and Miranda tries to prove to Grubbs that she's the right person to produce his album.

As Brooke angrily deals with Alexs tryst with Julian, Lydias condition worsens, prompting Quinn and Haley to try to reconnect with Taylor. Clay is forced to deal with Katies unsettling advances, and Nathan helps Jamie come to terms with Lydias impending death.