Have you ever been to a ballet dress rehearsal? It's very impressive. But this time, one of the dancers shows up cut in half so the dancing has to stop early. She wasn't actually killed by being bisected, though; her throat was cut and then she was hoisted into the rafters and wrapped with wire. The first suspect is Iris Lanzer, who took the dead dancer's lead role -- especially because the murder weapon was Iris's personal box cutter. Holmes is all giddy about meeting Iris, because she's a very important dancer, and she's got an alibi. So she's off the hook for now. Instead, the police focus on an ex-boyfriend.
The ex-boyfriend has an excellent alibi, and it turns out that Iris doesn't have an alibi after all. And when she announces that she's flying to Montreal to teach a master class, the police have no choice but to arrest her to keep her in the country. Her lawyer gets her out on bail and Holmes sleeps with her. Really! He claims that he was checking to see if she had a rotator cuff tear, but Watson is pretty sure he just wanted to have sex with a famous dancer. Sounds likely, right? The new theory is that someone is deliberately framing Iris, so Holmes starts investigating the many, many people against whom she has restraining orders.
At this point, Watson drops out of the main plot because she has to help a homeless person find what happened to his friend. This is challenging because it's hard to get a straight story when people have gone off their medication, but she spends much of the episode on her own investigation. She leverages Holmes's deep knowledge of tobacco to discover an evil couple that chains homeless people up in their basement so they can steal their aid checks. And it turns out that the reason she did all this was because her birth father is schizophrenic and out on the streets, so Holmes shows some compassion and offers to take blankets out to the park. It's heartwarming!
The only likely restraining order belongs to a sleazy photographer, but he doesn't seem to be an actual murderer. A voicemail turns up showing that Iris was having an affair with the dead dancer, and the photographer had spyware on Iris's phone, but he still seems innocent. In fact, he's got an alibi in the form of some hidden cameras that he snuck into Iris's bedroom. The investigation is stalled until Holmes does some technical work on the voicemail and discovers that it was leaked by Iris's lawyer. Eventually, he finds proof that he's the killer, because he was saving a hard drive with security footage from his crime. He was hoping to win a big exciting media-friendly trial with it, which is why he framed his own client. It's kind of elaborate, frankly.
There is coffee brewing at the Brownstone. A Post-In note on Holmes's bedroom door says, "Coitus in progress or recently concluded." Watson is getting used to Holmes's directness at this point, so she shrugs and walks to the coffee machine. A woman walks out of Holmes's room and Watson gives her some coffee in a to-go cup. Her name is Tatiana she has to leave and deliver a sermon. "She's a pastor of some sort," shrugs Holmes. That's twice in one paragraph that people have shrugged! Watson runs down some of Holmes's recent erotic escapades, which have involved both a mortician and a magician. She claims there was no judgment in her voice, but I think there was at least a little.
A ballerina gets ready. According to the officious (but deferential) woman with the clipboard, she's "Miss Lanzer," and she needs to be told that Vincent is ready for the rehearsal. And the rehearsal begins! It's ballet. There are toes and arms and legs and all that sort of thing. Two burly dudes pull on ropes backstage so things can descend from the ceiling. And there's a loud thump, which disturbs everyone. They're even more disturbed when they see that there's a dancer that's been cut in half, right through her waist.
The police swarm is in full effect. Holmes and Watson come to the stage. The press already knows about the situation thanks to Twitter. Gregson says the dead dancer's name was Nell Solange. There are security cameras everywhere, but they all fed into a single hard drive, which has been stolen. Vincent Renato (the director, I think) is called over, and he says he choreographed this dance with Nell in mind, although she had to be swapped out when she proved to not be up to the lead role. Holmes and Watson examine the body. There's not as much blood on the floor as you'd expect, because her throat was cut before she was cut in half. A wire was put around her waist so she'd be cut in half when the scenery came down. Watson thinks the blade was small based on the shallow wound, and Gregson suggests a box cutter. They're led backstage, where Bell has some discoveries to show them. Hi, Bell! He still can't carry a gun or work a case solo, but he's at least in the field. He shows them a spot where there were some blood drops in this spot, which led them to test the whole area with Luminol. Sure enough, it was covered in blood. Nell's body was hidden in a trash can, and Bell found a box cutter in the same can. They think it was wiped clean of fingerprints. Holmes notes an Iris etched into the side of the box cutter.