Olivia's chatting with the neighbor kid when Elliot strolls up, admitting that he "stepped in it" with the Fosters. Fortunately, this is not one of those times where "stepped in it" means "administered a savage beating." Olivia says Kathleen came back to the party after her shower but then left again with a couple of people from the party, one of whom texts the kid to say they were headed to Riverside Park.
That's where Olivia and Elliot find Kathleen, ditched by her friends, because it probably doesn't matter how drunk or high you are, sooner or later the chick wrapped in a shower curtain is going to get on your nerves. She's swinging pretty high on the swings -- probably trying to go over the bar -- while wearing a Roman toga straight out of the Bed, Bath and Beyond collection. Then she sees Elliot and gets excited: "Daddy! It's so cool you're here!" she shrieks, jumping off. She exhorts first Elliot and then Olivia to try to the swings, but the detectives have some brooding to do.
Later, Kathleen's in her room, brushing her hair. She's still wearing the diamond pendant when Elliot comes in, and she surreptitiously takes it off and drops it in her vanity drawer. Elliot starts questioning her, because she's in a lot of trouble for breaking into the house. "I didn't break in! That window was open!" Kathleen protests. Elliot says he's going to try to "fix things" so that they don't get worse, but she's going to have to talk to him, but Kathleen won't tell him who gave her the pills. And then she says it was the first time she tried anything harder than pot. "I swear, Dad! I'm sorry! I really screwed up, again!" she says, and then the lower lip starts to tremble, and I can confirm that your daughter crying is one of the hardest things in the world to watch, and Elliot hugs her. Kathy comes in with some hot cocoa, but Elliot doesn't stick around, preferring to find out who's pushing pills at Hudson University.
First stop: Kathleen's dorm room, where her bitchy roommate snots off about how high Kathleen is all the time and all the men she brings home, and a sloppily painted circle on the wall is testament to Kathleen's drugged-up desire to live "inside the sun." Elliot wants names of the men Kathleen's dated. "I don't know those losers' names. And I wouldn't call it dating." Elliot asks her which girl has been giving Kathleen pills. "Why are you asking me? I don't do that stuff. And I don't hang around with people who do. Like your daughter," she snaps, rather harshly, and you're kind of thinking, "At least Kathleen isn't a judgmental bitch," until the roommate breaks down and talks about how they used to be friends and stay up all night together. "She's in trouble," pleads Stabler, asking for her help. "There's this girl named Nikki Braithwaite," says the roommate.