There are guns in Starling City! I kind of thought there were always guns, but this time it's a big deal because a guy who calls himself "The Mayor" is equipping his gang with military hardware and they're driving around The Glades, shooting the place up. Felicity locates their hideout by activating a GPS that was hidden in the crate of weapons, but Oliver doesn't manage to take down the Mayor this time.
Oliver unmasks Black Canary by yanking off her mask and silly wig. And she turns out to be Sara Lance! The one who was supposed to have died on the Queen's Gambit in that big shipwreck that stranded Oliver on the island! She claims that she came back to Starling City to watch over her family, but she actually spends very little time watching Quentin or Laurel. She's actually more concerned about her friend Sin, who gets shot when the Mayor and his goons shoot up a cash-for-guns event that Oliver set up. Alderman Blood is also there, but Oliver keeps him from getting shot.
Laurel seems to be having some sort of a breakdown. First she gets arrested for driving drunk, although it was only a couple glasses of wine, and she doesn't seem to be driving unsafely. But she's a real jerk to both Quentin and Oliver when they talk to her about it, because she doesn't believe that recovering alcoholics could possibly have anything useful to say about the dangers of substance abuse. And by the end of the episode, she's washing down prescription drugs with a glass of wine, so you can imagine how crazy she'll be acting if she ever finds out her dead sister is running around fighting crime.
Once it's almost time for the episode to be over, Felicity suddenly discovers that a convoy of grenade launchers is probably going to come into Starling City and Oliver has to go stop it. He gets Sara to come help, and they do a good job of knocking out goons. He uses her staff, she uses his bow, and so on. Oliver shoots a grenade out of the air. The Mayor calls her a mean name, but instead of killing him, she just knocks him out. And we see a flashback where it kind of looks like she might be in charge of the boat full of soldiers that were bombing the island.
And then, at the very end, you will be shocked to learn that Alderman Blood is a bad guy. He's got a crazy rubber mask and a growly voice and injects a prisoner (the Mayor!) with a mysterious serum. And he's called "Brother Blood," which you can look up on the Internet if you need an explanation for.
Hey, Castle Queen is still around! I was wondering if they were avoiding that set this season. There's a party going on inside, of course. Felicity apologizes to Isabel Rochev (Summer Glau, remember?) for Oliver's lateness. We see that he's running around on rooftops being shot at by gang members with some kind of automatic weaponry. He uses an ankle-tangling arrow on one, so it's nice to see that he's got some non-lethal techniques now. Felicity reminds him about this party, but he's a little busy. When the fight's over, a goon is dangling from his ankle and won't say where they got the guns. Oliver reports that they were using M4A1 rifles, which are strictly military issue. Then he finally comes to his party, which is to attract investors to his company. He's got blood on his face, which doesn't impress Isabel.
Oliver does some mingling, saying hello to Laurel and Alderman Blood. Blood wants to talk about ending gun violence. The police already know who's been arming the gangs: the mayor. Oliver says, "I thought the Hood copycats killed the mayor." Well, there's probably a new one by now. It's not like once the mayor dies, you never get a new one. But actually it's a gang lord who calls himself, "The Mayor." He's trying to create chaos in the Glades. Doesn't sound that hard. It's kind of a chaotic place.
Somebody shoots up a mannequin in a strip club. This would appear to be the Mayor's hideout. Someone has spray-painted the words "CITY HALL" everywhere, because it's important for comic book villains to have a strong sense of branding. The Mayor exposits that before the earthquake, he was a weak man waiting to get fired and now he knows that the guy with the biggest guns wins. I'm not sure how an earthquake taught him that, but maybe he had to hide in a library. He's about to kill the guy who came back from the opening scene with Oliver, because he lost the guns. That guy's cousin asks for leniency, saying that he was the one who brought him in. So he gets shot, rather than his cousin. The Mayor, his homicidal nature established, says, "Let's hope you do your family better than he did."
Oliver finds Laurel at the party. She doesn't want to be asked if she's okay, and he does anyway. It's nice to see the show remembering that Laurel had a really traumatic time last episode. Although, as she says, "After the quake and Tommy, I should be used to that by now." And there was that time last season where she was almost gang-murdered in the prison. She's definitely having a rough couple of years. Felicity comes up to Oliver with something urgent, so Oliver shoos Laurel away. Felicity has a theory about Black Canary, who showed up at the DA's office and the kidnapping site: what if she's following Laurel, not Oliver?