Cox and Kelso still have some issues since Cox punched him a week earlier, and Kelso is still squeaking. Although JD is now starting with the third year; he still needs Dr. Cox's help identifying a patients problem, so the four of them do every single test trying to figure it out.

Turk and Carla set a date for the wedding, so JD wants to take Turk out for dinner to celebrate the end of an era, Turk has a problem with being straight with his feelings, until he sees a gay couple in the hospital. Carla finds a urine sample without a tag; she tries to find its patient.

Finding difficulties on training his interns, J.D. calls out to Elliot for some help. She indicates Sean, who gave Elliot great tips based on his dolphin training that fit perfectly for her interns.

Sean isn't happy to hear that Elliott & J.D. have been intimate. It does, however, make it easier for him to break some news to her. Cox applies for a promotion. Jordan hires a babysitter. Carla embarrasses Turk in front of other surgeons.

Dan decides to stay with J.D. for a while after their mom's new fiancée kicks him out, but after spending some quality time with him at the hospital, Dan isn't sure if he likes the cynical person his little brother has become.

Carla's brother who hates Turk comes for a visit. J.D. tries to get over Elliott when he meets Danni who *seems* nice. Cox asks J.D. to back him up in front of others. Kelso declares a policy Cox disagrees with. Will J.D. be loyal to Cox?

JD is dating Danni -Jordan's sister- and that means spending more time with Cox outside the hospital, and Perry doesn't very much like it. Danni tells JD that she is falling in love with him, but gets mad for the fact that he wasn't even listening.

The janitor has three personalities. No, actually four, or five. Cox and Carla get satisfied with their conditions. The first is getting old and Carla's marrying someone who goes to the arcade. JD and Elliot get a little bit competitive.

After Elliot gives a patient an orgasm during a pelvic exam and refers to patients 'private areas' using non-medical terms Dr. Kelso taunts her. Carla tells Turk that she doesn't think they should have sex again until their wedding night, the Janitor uses this information to his advantage.

Danni will move in -temporarily- to JD's. Carla and Elliot find out that a dying patient is still a virgin, and she wants to have sex before she dies, so they go out to find a man-whore. A patient of Perry's is getting a new liver, but Turk gives the opinion that the patient can't have the liver because he drinks.

JD tries to break up with Danni, but he never broke up with anybody. While Perry -for the first time in a long time- is happy, and that reflects on his behavior in the hospital. He has the problem of not having anybody interested in his lessons and teaching.

Dr. Kevin Casey the medical attendant AND surgeon comes to the hospital to impress them with his extraordinary medical skills, and his severe obsessive compulsive disorder case He also gives JD a hard time about his eternal search for a mentor.

JD and Kevin Casey find out about the roof toilet -aka- the epiphany toilet- Elliot needs help regaining her intubating skills, so she turns to KEVIN CASEY who helped everyone else And Turk asked JD to be his best man, so will JD be the best best man?

It's Jack's first birthday, so Jordan's siblings Dani and Ben are in town. Dr. Cox also tells J.D. to leave a patient for half an hour and check up on Ben's leukemia, but when a patient dies, Dr. Cox blames J.D., and takes over his patients.

It's a battle of the sexes when new female surgeon Dr Miller accuses Turk of being a 'sly sexist' and causes Elliot to question where exactly she stands in the feministic world. Carla is asked to teach a compulsory sexual harassment class with a few surprise students and a few not so surprise students. Meanwhile J.D inspires to help Dr. Cox grieve over his loss by asking Jordan's 'harpie' girlfriends to leave his house.

An ever present butterfly prompts the question of what could have happened differently while Turk searches for his missing lucky do-rag and Elliot hunts for her patient's stuffed toy.

J.D. and Carla are becoming closer; furthermore, they are "best friends". Dr. Ramirez, someone Carla used to like before he left the hospital, is back in town, and Carla goes out with him, not telling Turk. The Janitor is dressing up as his "twin" brother, Roscoe, to trick J.D. and Turk, but they won't fall for it.

JD dresses like a clown to fill into Elliot's shoes. Dr. Cox tries to have the hot Dr. Miller on his side in the war with Kelso. It's Turk's turn to take the narration -since JD is a clown and has nothing to say- and he is afraid of sending the invitations that mean that his wedding is finalized.

Sean comes back and takes Elliot from JD. JD goes back to Danni. The janitor works now as a security guard. Cox finds out that he has a crush on Dr. Miller and is tormented between his crush and his new happy family.

Cox is furious with Kelso for launching a lucrative "body scan" service at the hospital. Carla is becoming increasingly frantic about her impending marriage to Turk. Elliot is about to let Sean move in, but breaks up with him after J.D. confesses his love for her.

J.D. wakes next to Elliott, with the chilling realisation that he doesn't actually love her. At the dress rehearsal for the wedding, Turk is tricked into a humiliating gaffe by Carla's brother. J.D. chooses that moment to come clean with Elliott - who responds by throwing him across a table.

Turk and Carla's wedding causes tension between guests, especially Elliot and J.D., whose relationship had taken a nose-dive the week before. Turk attempts to work a little later to have an extended honeymoon, but will he make his big day on time?