Brownstone. Holmes watches some remarkably crisp security video of the subway pushing and regrets that he was in rehab at Hemdale when this happened. He wasn't allowed to see newspapers after the first day or so, which is probably a good idea. He notes that the pusher kept his face away from the camera, although subway pushers (which he calls "tube pushers" because he's British) tend to be impulsive. The police sketch from the witnesses is useless, since it just shows a hooded sweatshirt, sunglasses, and a beard. But the perpetrator had a weird patch on his jacket, which might help. Although they can't see the actual patch..
On her case, Watson is running up against a wall. She hasn't reached Drew, but she'll go to his art gallery tomorrow. She claims that she'll get to act like Columbo, which does not appear to be a reference that Holmes gets. However, Holmes is pleased that she'll call herself a consulting detective for the first time.
Emily (one of Watson's friends from that scene at the beginning) calls. Watson forgot about a dinner date, and Emily's kind of a jerk about it. They decide to meet at 8:00 tomorrow.
Watson accosts Drew at his art gallery. He says the worst thing about the whole situation is that Rebecca thinks he hurt Callie. The other time Callie left, it was for just a few days, and he got her to come home by begging. Watson pries into the problems they had, but Drew says he thought they were in a good place. Callie had seemed a little distant, though. He thinks it was something about the woman who got pushed that bothered her. I kind of hope Callie pushed that woman in front of the train. Shocking twist!
Watson has returned to the Brownstone to consult with Holmes. She has a tape of Drew from his first interrogation, describing the state of his relationship with Callie. It's the same words he used talking to Watson, which she finds suspicious. Holmes asks some questions to pick that apart. But there was still something that Watson didn't like about him. Holmes asks if she'd like him to tag in. Holmes likes pro wrestling? Or at least is familiar enough with it that he uses phrases from it? Watson doesn't want to tag out yet, but she asks what his next move would be. Holmes tells her about the concept of "Gaslighting," derived from the stage play Gaslight. Not the movie? Anyway, the idea is to make someone crazy by surrounding them with lies. It's fun! And it sort of relates to his plan. He's got a box full of burners, which are those disposable cellphones from The Wire. He pulls one out and texts Drew, "I know that you killed her. I know what you did with the body." Next step: follow him around. If this message scares him enough to get him to go get the body, you win! He recommends she rent a car. I think she probably owned a car at the beginning of the series, but I don't feel like checking. Now Holmes is going to go to the police station to interrogate someone related to the subway pushing..