The care free days are over for the former students of Tree Hill High as 4 years has passed since their last night on the Rivercourt.

[4] Peyton and Brooke move back to Tree Hill and meet Lucas' girlfriend Lindsay; Haley gives Nathan some tough love by threatening some precious to him; Lucas and Skills prepare Jamie to compete in a race car competition; Mouth gets a job but his boss Alice hates him.

[7] Peyton has her hands full with a musician who turns out to be very problematic; Mouth's in a relationship with his boss Alice and dating her is how he's keeping his job.

Victoria (Daphne Zuniga) pressures Brooke to make a difficult decision about the future of her clothing line.

[11] Tensions are at an all time high in Tree Hill as Lucas reached his limit with Peyton's rudeness to Lindsay.

[17] At the first Raven's basketball game of the season, Haley, Brooke, Peyton, Lindsey and Mia find themselves locked in the Tree Hill High library where secrets abound come forward.

Peyton learns a surprising fact that changes her mind about Lindsey while she and Haley try to help Brooke let go of Victoria.

Nathan uses the occasion to attempt a reconciliation with Haley, and recently-paroled Dan shows up for the family reunion.

[27] Lucas and Peyton discuss his aborted wedding, while Brooke gets a phone call that could change her life.

[29] Lindsey returns to Tree Hill for Jamie's fifth birthday party, giving Lucas hope for their relationship.

Until the show's return to the schedule, the network planned to post diaries online to fill in the intervening years in the characters' lives.

The strike was speculated to force television shows to end their seasons early, because there would be no future scripts until a settlement was reached.

"[3] On February 15, the CW announced that six additional episodes would be produced to wrap up the season due to the conclusion of the strike.

[11] Danneel Harris returned, as a recurring not main cast member, to portray Rachel Gatina, who is now a drug addict.

[31][35][37] Cullen Moss and Vaughn Wilson returned as Junk Moretti and Fergie Thompson, living with Mouth and Skills.

[4] Stephen Colletti reprised his guest role as Chase Adams, as did Kieren Hutchison as Andy Hargrove.

Newcomer Michaela McManus was added to the cast for a multi-episode arc as Lindsey Strauss, a "tough but kind" New York editor assigned to work on Lucas' novel.

[42] Daphne Zuniga guest starred as a "glamorous and intimidating" business exec who works with Brooke,[42] later revealed to be her mother.

[7] Torrey DeVitto has signed on to play the nanny of Nathan and Haley's son in a multi-episode arc.

[41] Kevin Federline appears in a multi-episode arc this season playing Jason,[44] as well as singer/songwriter Kate Voegele who portrays Mia.

On November 6, 2007, The CW posted the first One Tree Hill online diary, a series of six segments to be released before the start of the new season.

One Tree Hill Fast Forward allows fans of the show to catch a glimpse of the lives of the six main characters at the beginning of the fifth season.

[41] The second diary, posted on November 13, featured Chad Michael Murray's character, Lucas Scott.

[41] The fourth diary, posted on November 27, featured Lee Norris's character, Mouth McFadden.