Dan must face the harsh consequences of his decision to murder Keith as Karen and Haley's pregnancies complicate the lives of Nathan and the graduating seniors of Tree Hill High. Lucas wrestles with his post-high school options, and Peyton and Brooke prepare to spend the summer in Los Angeles together.

On Lucas and Lindsey's wedding day, Peyton must choose between intervening and losing Lucas forever. Nathan uses the event to try to mend his marriage to Haley. All are shocked when Dan, who is out of prison on parole, shows up at the event.

Lucas picks up the pieces after being left at the altar by Lindsey, while Nathan and Haley deal with the repercussions of Jamie's abduction. Dan is free for now, but he must find himself a job to convince the parole that he is changed for good. Brooke is haunted by her past as a woman from adopting asks her questions, while Peyton gets a visit from an old friend.