Turk and J.D., bonding with each other, along with their kids, say that they haven't spend much time hanging out with each other, since they're preoccupied with their babies. Turk suggests that the two of them pull off a great prank, in an effort to bond with each other better. The two then decide to be the "World's Tallest (African American) Doctor". They get all the props ready, such as a giant stethoscope, pencil and clipboard. J.D. goes off to Dr. Cox and displays these props, only to have Dr Cox chide him for not growing up and acting mature, reminding J.D. that he wanted to "grow up" back in "My Inconvenient Truth". J.D. becomes depressed and calls of the prank, though Turk begs to differ.
Turk decides to bring back the playful spirit in J.D., and attempts to do so by playing games such as Following Hooch, and Find the Saltine...But J.D. just gets more annoyed and questions why Turk is doing this to him.
In another storyline, Dr. Cox tells a young boy that he has leukemia, against his parents' wishes. Though the boy appreciates that Dr. Cox told him the truth, Carla is still mad at him, though Dr. Cox doesn't know why.
Dr Cox and J.D. go into the cafeteria and confront Turk and Carla respectively. Turk tells J.D. that though it was necessary for J.D. to grow up, he didn't have to change who he was...he just had to take more responsibilities (which he was already doing) and shouldn't abandon his true self. Carla then tells Dr. Cox that the young patient, would have found out eventually, but it was wrong of Dr. Cox to take away his childhood with this unpleasant news.
In yet another storyline, Elliot and Janitor throw Kelso, who's reluctant about revealing his age (which turns out to be 65). During the party, one of the Board members finds out about Kelso's age.
The episode ends with J.D. and Turk pulling off the prank after all and Cox playing with his son. The Board Member then tells Kelso, that he has to retire, as he has reached the retirement age, for his job.