So the detectives delve into the case file; Elliot figures a smarty-pants engineer like Rook could easily tamper with brakes. Warner reviewed the autopsy and says the doctor's blood-alcohol level was .04, which wouldn't be enough to make the liver-cirrhotic doctor drunk. No sign of brake tampering either, and one of the forensics guys cues up the Pole Position-looking computer recreation, in which the doctor's car actually sped up before it hit the semi. So ... tampering with the gas? The death was ruled a suicide, since the doctor left a note and everything, saying he wanted to spare his wife: "Det. Milgram won't stop calling me. He says I'm going to prison for murder. I never meant to harm that woman and her baby. God forgive me."
In case everyone else is an idiot, Olivia says Rook pushed the doctor to suicide. So they'll dump his phone records, and that plus the note should be enough, right? Hold on, says the non-Warner forensics guy, who happens to be on Rook's website, which is exhorting the non-sheep to all go to Grand Central Station tonight for the most fun yet.
When Elliot and Olivia get there, there's no sign of anything going on, so they split up. Then, the leader of the Bryant Park rally yells over a megaphone "No sheep!" And several of the people in Grand Central freeze in place. Wow, consider my world sufficiently rocked, you guys. Way to make me question my conformist values. Olivia spots Rook, radios Elliot to come meet her, and tells him he's under arrest for the murder of Dr. Slifkin. Rook mournfully says he was a sheep and let the doctor slaughter his family.
The freeze flash mob ends as Elliot's making his way over, and he suddenly proves incapable of making his way through the actually-rather-sparse crowd. And Olivia's not where she said she'd be. Instead of taking out his radio, Elliot stands there looking around.
A swat team followed by the detectives bash into Merritt's apartment. No one's there. Chester shows up with train station photos of Rook leading Olivia out of the station, with her dumping her gun and cellphone in the trash. Elliot figures Rook had a gun on her and she didn't want to risk him shooting civilians.
Desperate to find where Rook might have taken Olivia, Elliot heads over to Aerodax to question Dr. Chang, who was the co-worker Rook didn't want to find out about the prostitute. Turns out they went on a couple of dates, including one memorable one where Rook took her to a jazz club to watch a friend perform. Then, when the friend played "Lush Life," Rook burst out crying and left. The friend came over later and apologized, saying he forgot he'd recorded that song with Rook's wife. "Juliet was a singer," says Elliot, and Dr. Chang says they met when Rook produced one of her albums, which is what he did before he moved into aerospace, over at Tone Down Records in Brooklyn.