Holmes's latest thing is that he doesn't want any unnecessary information cluttering up his brain. This, he tells Watson, is why he doesn't play violin anymore. He needed to keep the mental space available for, you know, crime facts.
The case of the evening involves a young man who's been shot through the head in an apparent robbery. Except the only robbery was the guy down the hall stealing the antique armoire. But there was definitely a murder! Holmes thinks it was a woman, because his sensitive nose has detected a lady's deodorant on a chair.
The armoire thief says he saw a woman, and a sketch is made over the objections of this week's skeptical cop. The sketch matches a woman who's been a coma for three days. So it can't possibly be her! (Spoilers: it actually was her!) She's got a fraternal twin, but she's got a pretty good alibi, too.
Another victim turns up, and Holmes employs his brilliance to identify her as the first victim's half-sister based on subtle clues like a similar hairline, bone structure, and extremely rare genetic disorder. And it turns out that both victims were half-siblings of the twins we met earlier and stood to somehow inherit a bunch of money. So far, it seems like everything would have unfolded about the same way regardless of whether Sherlock Holmes was involved.
But then Holmes is stuck in a rehab meeting and he's so bored, he actually listening to the stories. And that gives him a brilliant idea! Eventually, Holmes sets an extremely obvious trap for the one in the coma, where she thinks she's killing yet another long-lost heir. It turns out that she was being given coma-inducing drugs by her doctor boyfriend, then brought out of it the same way when it was time to kill. It's the perfect plan! Assuming you want a killer who's constantly woozy from being given coma-inducing drugs!
Oh, and Watson has a date with an ex-lover. Very little happens. At the end of the episode, Holmes plays his violin again, which Watson appears to take as some sort of victory. I don't think the neighbors feel the same way.
We open in a rehab meeting. I don't know what they're actually called. It's one of those deals where someone stands up and tells stories about how their addiction affected their lives. A "support group meeting"? Anyway, Holmes and Watson are sitting in the traditional uncomfortable chairs while a young man tells them (and us) that he's been sober for a specific length of time. He goes into detail, but it isn't very interesting. And that's not just my opinion! Holmes shows absolutely no facial expression or reaction. Apparently he repeats "amygdala" to himself until he hypnotizes himself, then he just rides the trance through the entire meeting. If you're curious, the "amygdala" is the part of the brain that is involved in emotional learning, so he's literally using the name of the thing to keep it from working.
After the meeting, Holmes explains his "attic theory" of the brain. He finds it essential not to allow useless facts into his brain, because they'll push out the useful facts. He demonstrates this by stealing drinks from a surprisingly patient lady at a sidewalk cafe. You see, brains are like glasses and facts are like liquids. If you pour too much in, they'll overflow! I want to know more about this woman who has nothing to say about a crazy man stealing her drinks and pouring them into each other.
They get home and Watson tells Holmes she'll be going out to dinner with a friend later on. Holmes is lavishly sarcastic about how she could possibly leave him alone for two hours, but she assures him he'll get a drug test as soon as she gets back. But! Just then! Holmes gets a call from Gregson, which means the game? It's afoot.
The scene: an apartment building. The victim: some guy with a bullet hole in his forehead. He's outside his actual apartment, out in the hallway. The police figure he interrupted a robber, who shot him. Gregson introduces Detective Bell, who's this week's Doubting Cop. Do you think we're going to get a new Doubting Cop every episode? Or is it going to be like the first season of Batman: The Animated Series, where that one cop was suspicious of Batman the whole time, even though Batman was always right and kept saving his life?
Anyway, Bell claims he's heard good things about Holmes. And now, onto the case at hand. There's a neighbor down the hall who called 911. Watson says she'll wait in the hall, because now she's queasy about dead bodies or something. Holmes looks at the blood spray on the wall and sniffs the furniture. Then he shouts at Bell to tell him that it wasn't a robbery-homicide. It was two separate crimes! His evidence is that the shot came from the direction of a chair, so the killer was sitting down, rather than being surprised in the middle of a robbery. Also, he can smell a lady's deodorant in the chair where the shooter was sitting. Meanwhile, the robbery was committed by a strong man. The evidence: he didn't just steal a wallet and a watch. He stole a heavy armoire.