Roy gets home and tells Thea he has a new plan: stake out his pal who sells vertigo. That's still on the street? I thought the whole deal with vertigo is that it only showed up when a villain was making it. And he's not afraid of Oliver, because he's "kind of a wimp." Oliver doesn't look or act remotely wimpy. There's no Clark Kent here. Thea protests that she almost lost him. Roy: "Yeah? Well I lost someone too. And they aren't coming back." I notice he's using the singular "they" here. You normally see that when the speaker doesn't know the sex of the person they're talking about. Like when I said "they're" to refer to "the speaker" in that last sentence. But there are people who prefer not to be referred to by either "he" or "she." It's possible that's what's going on here. But if it's a single person that Roy lost and the writers just want to keep that person's sex a secret, it's really odd for Roy to say "they." So there. Roy says he wants to learn to be like the vigilante. Better start slapping some water, pal. Thea threatens that he has to choose between the vigilante or her. He chooses the vigilante instantly. So I guess this relationship that we've never really seen is now over.
Moira is checking on Walter. He hands her a letter of divorce. What a shocking twist! He doesn't believe that it was a coincidence that she told him he was too close to her conspiracy, and then he was kidnapped later that day. Seriously. Moira says that saved his life, but he thinks she destroyed it. He dares her to convince him that everything he knew in his whole life hasn't evaporated. Well, probably not everything. Thea comes in and asks where he's going. She's instantly freaked out, and he hugs her. Then he leaves. Moira is distraught. Thea's really sad, too. We never really saw her bonding with him, but she's doing a good job of convincing me that it must have happened offscreen.
Police station. The resident hacker tells Quentin that Merlyn Global cyber-security is off the charts. Why are they hacking in? They're the police! And they were supposed to be getting a court order! But instead, we have this guy whining about firewalls. But while he was trying to get in, he saw that someone else was reverse-engineering footprints. And he knows who it was: Felicity Smoak of Queen Consolidated IT. Did she leave her name in there? Seems sloppy. I'll be interested to see if the police decide she was doing some corporate espionage.
Arrowlair. Felicity gloats that she uploaded a Trojan while she was in there. She's trying to locate the seismic device, but "There's at least a teraflop of data to get through." Flops aren't data, they're processing speed. And what did she download, exactly? Her tablet computer isn't going to hold a ridiculous amount of stuff. Oliver holds the notebook and says that the List isn't his goal anymore. He thinks he was treating the symptoms, not the disease. His new plan: "I stop the Undertaking, I wipe out the disease." I don't see how. Most of the things he's done haven't had anything at all to do with the Undertaking. But now he thinks if he stops the Undertaking, he can hang up the hood. He says, "Merlyn's plan is what I returned from the island to stop." Then he heads for the door. When he's asked where he's going, he just says, "Out." He has very little respect for his partners here.