Super-dad Nathan prepares training-buddy Jamie to being 'the man of the house' while he's with his pro team. Julian has a fun and games with Brooke, who believes ma's shenanigans wrecked the fashion firm by irreparable image damage. Chase is now courted by both Alex and Millicent. Clay has a nightmare before he stars a wonderful beach day with Quinn, only to find it come bloodily true in the end by Quinn's vicious hand.
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.
In hospital, Quinn starts a full recovery, but Clayton's situation looks hopeless unless he gets a kidney donated faster then is likely. After getting Jamie's blessing and consulting Haley, Nathan volunteers his own, even if that probably ends his basketball career, which is likely to be broken off soon anyway as he back injury worsens again, but is diagnosed incompatible. Julian and Brooke are delighted, yet suspicious if they can believe it, that she get off with a fine and some restructuring. Fraudster Victoria arranged this, willing to go to jail herself. ...
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.
Nathan decides, after checking Jamie and Haley will support him, to leave basketball on account of a medical condition. Clay has transferred his clients 'during recovery' to his old agency, but approves of last star Nathan's choice, which is then announced on TV. Chase is far from amused discovering that the job he gave Alex is an ideal preparation for a part she never told him about. Julian supports Brooke, who gets flack from ma in jail, when she decides to sell the company and private assets to pay all investors back. Julian also starts a documentary and takes ...
Clay is released home, but still physically unable to handle his clients. Nathan provides moral support and considers approaching them as fellow locker-room insider. Even super-dad can't prevent Chuck Scolnik vindictively scaring Jamie away at Halloween from a 'ghost house'. Julian's domineering ma brings embarrassment for him at a costumed party in Chase's bar.
Nathan is furious when his first mission as Clay's junior agent seems to go wrong because of his lack of jargon knowledge, but he actually lands the football client. Julian accepts Alex's suggestion to assemble all potential best men for a friendly poker night, but the mood is murderous. Chase gets abused by everyone. It's Brooke's turn to by bullied by Julian's bossy ma, who pushes for a traditional wedding at a brides fair, where Haley sides with the enemy every time.
Clayton finally gets some hand muscle control back. As he predicted, Nathan had no reason to be gloomy about his first contract, baseball talent Troy, which is signed to all parties' satisfaction. Julian and Brooke stand up to his ma, 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 super-dad's absence, Jamie finds it even harder to face the peril of braces peer ridicule, which Haley only compounds by wearing a 'commiserative' eye-patch.
At Thanksgiving, only Chase mans his bar, but gets no customers, while his rivaling would-be-girlfriends bicker ever worse at Nathan's, only to agree he should decide, actually on Julian's video. Brooke utterly ruins her first turkey dinner, so Julian takes her and his ma along to Nathan's, where Clayton still stays. Portions were cooked there for more, and indeed Mouth turns up with Skills, who bought a live turkey although neither has the guts to kill it, and later Quinn. Victoria is released from jail, and Sylvia invites even her.
Nathan goes back to college and opts to take a harder class but he doesn't get a very welcome reception from his college professor and so with Jamie's help they figure out a way for Nathan to do better at college. Haley and Mia book Erin as warm-up act to Kid Cudi at Tric with both Mia and Alex acting as competing bar staff. Elsewhere, Quinn looks up Dan Scott and enlists his help to kill Katie Ryan but he manages to talk her out of it but she may regret her decision as Katie heads back to Tree Hill. Julian finds a list belonging to Brooke of things she's always ...
While Nathan dutifully studies a book by professor August Kellerman, the girls pig out so grossly at Brooke's hen night that hangovers are their least concern. More worrying are (or seem) the arrival of mother in law Sylvia, a stolen dog, it's owner vandalized home, a frat and the missing engagement ring or even bridal infidelity.
Julian gets his parents to agree to a truce during his wedding. Brooke makes up with ma, and when her dad fails to turn up, as usual, is escorted by Julian's. Super-dad's advice of sincerity helps inspire 'best man' Jamie to make a brilliantly simple speech. Chase not only disagrees with Skjills' absurd security-obsessed job description for them ushers, he even makes hotter use of the limousine.
After standing up for a fellow student ridiculed by bully business professor Kellerman, Nathan joins a study group of guys hating him and fields his secret weapon, real executive Clay. Chase feels his barman lack social relevance and volunteers nobly for the big brother program. Alas he draws Jamie's terror mate Chuck, who haughtily belittles every cool activity, even flying, and abuses Chase as punching ball, until big bro deciphers his charge's frustration. Julian is directing a local TV commercial, where the 'star' gives notice, but thus finds an opportunity for ...
Winning Chuck's trust, 'big brother' Chase learns his charge's revered dad made no contact in two years. Chase shields Chuck from lush ma Skolnick and encourages his show-tune ambition. Nathan won't let Clay give up yet on professor Kellerman's son Ian, who figures his baseball arm won't last long, so he opts for immediate profit. Meanwhile their wives make wrong assumptions on Valentine plans, yet aren't disappointed in the end. Julian and Brooke enjoy spending their first married Valentine's day in role play, although some reality knocks on the door, and decide to ...
Nathan and Clay's patience is tested by possible recruit Ian Kellerman's party priority, but they find it assisting at Jamie's little league baseball try-outs, where hothead Chuck fails miserably. Julian would play up-front when a single mother considers them to adopt her unborn baby, but Brooke gets them caught in elaborate prefect couple lies during a surprise baby-shower she hosts for Haley.
Nathan and Clay are finally ready to sign up Ian Kellerman when his pa, professor August, asks Nathan, who finally got a good grade, not to. Finally enjoying the scamp's trust, Chase helps Chuck with his baseball by borrowing Alex's spectacles. Julian, Brooke, Quinn all got their turn with false pregnancy alarms from Haley, only Nathan and Clay are prepared. Now Chloe Hall has accepted them as adoptive parents, Julian and Brooke prepare the nursery. Mouth inspires Millicent to turn her lame TV job in a chicken suit into a social conscience, which proves quite a risk.
While the gang waits for the birth of Jamie's sister, their thoughts wander, further stimulated by Jamie's questions. Reminiscing abounds, such as Nathan's determination to become as good at fathering as Dan failed to be his. Julian and Brooke discretely slip away to another delivery, that of Chloe's baby, but to their shock the father, Eric, isn't a runner but present, charming and caring, passing muster when discussing paternity with unsuspecting, supportive Nathan.
Nathan discovers the drunk hit and run car in professor August Kellerman's garage, and an empty whiskey bottle, and confronts him with near-victim Jamie and Julian. They obtain his academic resignation and a confession he regrets having been an absent father for Ian. Now the adoption is off, Julian and Victoria encourage Brooke to accept a dream job in New York. Chase supports Alex's slow music career launch. The gang nostalgically agrees Mia's next TV item should be a building project at the sight of the river court. Ian's favorite drink arouses a dark suspicion.
Nathan gets professor August Kellerman to confirm the truth: he resigned as if guilty to cover for his son Ian, like Dan's sole true paternal sacrifice. After coaching Jamie's team, Nate, Julian and Clay take Ian there for a bitter confrontation before his crucial scouts-mustering. Chase has to miss the game.
To save the River Court, Nathan mobilizes the boys, even Clay who prefers very specific homely comforts, to camp out in search of the elusive protected bird species, so they can halt the construction project. Chase is overheard by Chuck about joining the Air Force. Before Chase can reason with the imp, a bulldozer frenzy wrecks seemingly everything, yet proves a long-term blessing. Meanwhile in Puerto Rico, the girls have a blast modeling, but Jamie's teacher gets drunk, ultimately sending 'delicate' pictures of herself to all her One Tree Hill contacts.
Haley and Brooke get ready to re-open Karen's Café as Brooke's pregnancy progresses. At her scan she discovers that she is expecting twins. Nathan and Clay set off on the road to scout new talent and it forces Nathan to finally go and see Dan. Chase leaves for the Air Force leaving behind two disappointed people - Chuck and Alex. Meanwhile, Mouth and Millie start their new morning show together but Millie is wooed away to start a new show with another co-anchor in Charlotte.