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 wanted to do but never got around to so he sets about making them all come through so that she gets her lost inspiration back.

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.

Brooke, Quinn and Haley decide to use their talents for the greater good. Meanwhile, Julian takes on a directing job and helps out a friend, and Chase mentors Chuck.

As Haley's due date approaches, she takes steps to ensure that all her friends and family will be ready when the time comes. Brooke and Julian also prepare to begin a family, while Chuck turns to Chase for help with a problem.

While Haley stays at home to take care of the new baby, Quinn organizes a concert at Tric. Meanwhile, Brooke gets an offer to return to Clothes Over Bros, and Nathan sets his sights on exposing Professor Kellerman.

As Nathan, Julian and Clay coach Jamie's first little league game, the situation regarding the accident comes to a head. Meanwhile, Chase asks Alex to take a drug test for him, and Quinn gets an offer to shoot in Puerto Rico.