Police station. Holmes has a picture of the weird patch that was on the subway pusher's coat. It's labeled "1960s Psychedelic Patch" and reads, "If you feel like you have to... don't." But the bigger issue is that Gregson says that if Watson will apologize, Drew will drop the charges. I like the dynamic here. When Holmes is confident about something, the police look like idiots when they don't listen to him. But Watson doesn't have the track record, so it's plausible that people wouldn't back her up. She's in a crisis of confidence and walks out to apologize to Drew. Holmes watches.
Knock knock knock! Watson has come to meet Rebecca. She's here to apologize for getting too aggressive with the investigation and report that she thinks Callie left on her own after all. Then she notices a digital photo on a shelf. Callie's wearing a coat with that patch. The coat is Drew's. And Drew used to have a beard. Why, these two unrelated cases aren't unrelated at all!
Brownstone. Specifically, the crazy-person wall. I'd like to see a scene where the yarn connecting the photos and clippings is actually explained. Usually we just zoom in on a picture or something. Why not have the connections matter? Holmes considers the facts. Drew Gardner had a beard and the right jacket. Then Callie left Drew, saying the murder affected her. Why? How did it affect her? Could he have planned to kill Vivian Tully to cover up the subway thing? Or something? Watson moans about how she's wrong all the time, and I love Holmes's response: "Have I told you how distracting I find self-doubt? If you must wallow, I ask that you do it in the privacy of your room." Even when he's respecting her opinions, he finds a way to be a jerk about it.
So! What could Drew's motive be to kill Vivian? And how would it compel Callie to leave her husband? How does the one thing lead to the other? Well, Watson suggests that it could go in the other direction.
Interrogation room. Drew is confronted with the subway-pushing case, and the evidence that his army jacket had that patch. Drew claims to have given his old army jacket to Goodwill. Holmes says that his wife left him once before. She made the video the first time she left him. When she said "the woman with the flowers," she was talking about a woman named Anne Peters who got shoved into a train by some kids. She was carrying flowers she picked from her own garden. Drew gave Vivian Tully the flowers to recreate a situation that matched the wording of the recording his wife had already made. He just needed "a pushing involving a woman holding flowers." Drew says Watson is just some crazy woman. Gregson asks if he's sticking to his story that the video is only six months old. He is. But they have access to her email. He deleted it, but they found it archived in the server. The video was originally sent eighteen months ago, just after the other subway pushing. Holmes gives Watson an approving nod.