Carrie is tormented because she can't stop thinking about Aidan. She admits to the girls that she wants him back. Miranda suggests emailing Aidan. Carrie gives it a go and writes "I miss you" in her first message to Aidan.
Miranda meets a cute guy, aka "Marathon Man," in her running group and they arrange to go for a run together, which leads to a post-workout workout. Miranda is surprised when Marathon Man puts his tongue where no man has gone before. Charlotte has other things on her mind as she and Trey talk about having a baby. However, when she invites over a couple with three kids, the reality of parenting looks a little less appealing and Charlotte and Trey take a break from their attempts to procreate.
After 36 hours, Aidan still hasn't responded and Carrie breaks down and calls him. She arranges for them to go out with Miranda and Steve. After dinner, she tells Aidan that she wants to get back together with him. Aidan says he can't do the relationship thing. Undeterred, Carrie returns to his apartment later that night and tries to convince him to give her a second chance. Aidan finally just screams, "You broke my heart" and Carrie runs home again.
Over at Miranda's apartment, Marathon Man not so subtly tries to get Miranda to do some reciprocal licking, but she realizes she just can't. At the next marathon training session, she races right past him. Samantha, who has been sleeping with MBA man, Warren, is turned off by his baby talk in bed. When she suggests he stop, Warren takes offense and storms out like the big baby he is. Speaking of babies, Charlotte and Trey decide that one baby will be okay and get back to work.
Back at Carrie's place, Aidan shows up and without any words, the two have passionate sex. In the morning, Carrie tells him that she still loves him and wants to be his girlfriend, but Aidan says he needs to think about it. Later that day, Aidan returns and says, "Ok, let's give it a shot."