Oliver's first case is a slumlord from the Glades. But before he can hunt him down and threaten him with death, some other weirdo gets in there first. And instead of just threatening death, this guy actually kills the slumlord. And he broadcasts it on video to all the cellphones in Starling City, because he's kind of crazy or something. I don't know. Anyway, Oliver objects to that on the grounds that one murderous vigilante in this town is enough.
Laurel, meanwhile, is consumed with a Lance-centric plot in which her parents Dinah and Quentin search for evidence that her sister Sarah maybe didn't die in the shipwreck. They've got a picture that looks like it might be her, but it turns out to be some other person entirely. The whole point of the storyline appears to be the revelation that Dinah saw Sarah just before she got on the ship. Also that Dinah lives in Central City, which is where The Flash is from. Not that I expect to actually see someone running faster than light on this show, but it's fun to have some of the outlying geography of the DC Universe get added.
Thea's making out with Roy now, because she's got a thing for bad boys. And this turns out to be inconvenient when Roy gets kidnapped by the new vigilante in town. But by the time this happens, Felicity has figured out that the new vigilante is broadcasting from a disused subway car, which means that Oliver can break in and have a manly vigilante-to-vigilante talk with the new guy. Oliver earnestly explains to the new vigilante that killing is not the answer, and then he kills him. And Roy lives! So Thea's got a new boyfriend. And instead of having a damsel in distress, Oliver had to rescue one of the male members of the cast, which is a nice change of pace once in a while.
On Flashback Island, Oliver's plan to trade the missile launcher's circuit boards for a way off the island does not go as planned. General Fyers manages to find the boards where Oliver hid them, so that's bad. But there's a botched hostage situation in which Slade and Oliver manage to escape with Yao Fei's daugher. So that's good! But Yao Fei gets shot in the leg and can't escape with them. So that's bad!
We open in the Arrowlair, where the same television news broadcast that's always playing tells Diggle and Felicity that the lawyers for John Nichol are happy that he won't be prosecuted. Oliver is doing pointlessly showy shirtless pull-ups on a catwalk overhead, and he exposits that John is one of the richest and dirtiest real estate developers in the city and it's his fault his building burned down. During some of this, he's hanging by one arm. He gets bored very easily, I guess. The point is that the police can't do anything because the buildings are in the Glades. There's no explanation for that explanation. Anyway, he's on the List, so it's time to deal with John Nichol, Arrow-style. Felicity is on board, since she has a strong objection to slumlords that has never been mentioned before and will never be mentioned again.
Mr. Nichol is a heavyset bearded man who lives in a giant building made of glass. He hears a noise and creeps downstairs with a kitchen knife. This doesn't help, because he's knocked over and dragged off. But not by Oliver, who shows up a little too late. When Oliver gets there, he sees a knocked-over lamp and the knife on the floor. Meanwhile, Nichol is getting loaded into a van down at street level.
Arrowlair again. Oliver is angry that Nichol had been taken by someone else, so he wants Felicity to generate a list of Nichols' possible enemies. He admits that there are probably a lot of them. Felicity uses the phrase "Grr! Stop being bad or I'll Arrow you!" to describe Oliver's tactics, and asks why he's mad that somebody else is out there doing basically the same thing. Oliver explains that he doesn't like the idea of another vigilante out there because, in his words, "typically, they don't show my level of restraint." What restraint? You kill people all the time! Oliver decides not to cross Nichol off the list, but he's got green balls (a vulgar phrase that I have just invented) and wants to go after someone else on the list. Diggle makes him go eat dinner instead.
Flashback Island, right after the last episode. Fyers offers a boat in exchange for the circuit board, but he says it'll take time. Oliver starts to give him just an hour, but Slade overrules him. Geez, Slade -- you said it was Oliver's call. Let the kid fail on his own or he'll never learn!
Roy Harper's place, which is a mess. And it contains Thea Queen, who's making out with Roy. Their relationship has jumped forward with no warning! A sketchy (but well-groomed) guy comes to the door and gives Roy a package, along with cryptic hints about something happening tomorrow at 11. Thea grabs the package to discover the pistol inside it. Roy is knocking over a liquor store tomorrow! He explains, "I owe people. People with much bigger guns than this." He offers to take the bullets out, which at least means he won't be shooting anyone. Thea flounces out.