The NYPD has decided to cut ties with Sherlock Holmes, because Gregson does not approve of the way he was going to torture and murder Vinnie Jones in the last episode. But that just means that Holmes doesn't have anything else to occupy his time, so he tries going online to troll conspiracy-theory forums. This, of course, results in him going to the house of the moderator (don't do this, kids!) and finding him dead. So the police have to get dragged in after all.
While investigating the scene of the crime, Holmes grabs a tortoise. And in the terrarium, there's a high-tech listening device, which means that one of this guy's unlikely conspiracy theories is probably true! Holmes decides that it's one about "The Red Team," which is the belief that a US Army team came up with a brilliant theoretical plan for attacking New York. To prove his theory, he tracks down members of the team, and they turn out to have been killed in suspicious muggings or come down with convenient cases of Alzheimer's. Well, two of them did, anyway.
The remaining members of the team are tracked down by Holmes, and none of them are willing to talk. He does meet a friendly fellow named "Billy," who will neither confirm nor deny that he's involved with any security organizations. Billy is really an officer codenamed "Yossarian," but he dies right away. Holmes has all the remaining characters moved to a hotel, which immediately backfires when one of them turns out the be trying to kill the others to keep the secret plan from getting out. And he's got a hostage!
Holmes gets himself into the hostage situation, and he breaks things up by telling the bad guy all about the secret plan. We don't see it, so don't worry. Then Gregson punches Holmes in the stomach and lets him come back to consulting with the police. Which is great news for Holmes, but it ruins the excuse that Watson was using to keep staying with him although she's no longer being paid as a Sober Companion.
Holmes has covered his wall in Moriarty stuff. But the rest of the Brownstone is clean, which gives him an excuse to complain about Watson. He refocuses on his wall, which has an incongruous picture of Napoleon Bonaparte. This is a reference to Moriarty being "the Napoleon of Crime," you know. I like that even though this show isn't particularly interested in being faithful to the canonical Sherlock Holmes, it has a lot of references to Arthur Conan Doyle's stories.
Holmes has been asleep for two days, which has left him hungry, so he's cooking up several eggs in a wok as he explains that he likes to go on websites and stir up conspiracy theorists. He's going to claim that Washington, D.C., is moving to Omaha, which will soon be beachfront property because of global warming.
While Holmes is trolling people on the Internet, Watson is at therapy. She thinks Holmes is ready to deal with Irene. But her therapist wants to talk about how Watson is lying about her contract ending. And she's not being paid for her time, so she's dipping into her savings to support this lie. Watson gets a text from Holmes, but before she goes, she explains her logic: Holmes has been fired from the police, so if she can restore that relationship, she'll be able to quit with a free conscience. She's just sticking around until she can restore Holmes's normal situation. Honest!
Holmes welcomes Watson to the home of "Zapruder," the moderator of the conspiracy theory forum. His actual name is Len Pontecorvo, and the other people at the website feared the worst when he declined to get involved in a crazy argument. Like every apartment on this show, his place is huge and amazing. And Zapruder is hanging from a piece of exercise equipment (I think) with his pants around his ankles. This dead person is not particularly surprising.
Once the police are there, Bell is a little annoyed to be back with Holmes. He was under the impression that when Holmes was suspended from working with the police, he'd stop working with the police. Holmes points out that the belt around Zapruder's neck is bigger than the one he'd actually use on his waist, and that his index finger looks too hurt to buckle a belt around his own neck. He'd like Bell to have the Medical Examiner check the neck ligatures for evidence of murder. And to make it easy, Holmes has already texted the Medical Examiner. Bell is frustrated, but he'll allow it. Watson and Holmes go off to search the house. Watson wants to check out these neatly labeled binders over here, but Holmes already knows what's in all of them. There's also a tortoise in a terrarium. His name is Clyde. Holmes takes him because he's going to be abandoned and die. Also, he claims because he wants to have some turtle soup later. As he's taking Clyde out, he finds a secret electronic doojiggy in a rock. It's a bug, which means someone was listening in on the conspiracy nut.