In the "Arrow" episode "Vertigo," Oliver is feeling vengeful about the street drug that nearly got his sister killed. Digg remains the voice of reason, and Oliver and Thea learn it's good to have friends in all kinds of places.
Arrow uses his powers of persuasion on a drug dealer to get a name in relation to Vertigo: The Count. Before Oliver has a chance to pursue it, Digg reminds him it's more important to be at his sister's DUI hearing. His moral support is welcomed by Thea, but it's not enough. The judge decides to make an example of her and jail time seems imminent.
Oliver hopes that bringing down the Vertigo operation will be more important to the crime-weary judge than busting an 18-year-old first-time offender. He lines up a Plan B, however, surprising Laurel by asking her for a favor from her dad. Despite the long odds on Detective Lance helping Oliver, she agrees to try.
Laurel appeals to her dad on behalf of Thea, who reminds her of her sister Sarah. He's offended by the comparison, but she insists that his rosy memory of his daughter is far from the truth. She also notes that Sarah was just as responsible for being on that boat. Laurel asks him to put in a good word with the judge, for a troubled girl who needs help, not time in jail. He reluctantly agrees.
Oliver is relieved when the judge offers community service and two years probation. Unfortunately, Thea is so messed up that she refuses the plea deal because she wants to punish her mother for cheating. Oliver finally tells her that Dad wasn't such a nice guy after all, upsetting her and angering his mother.
Leaving his family in turmoil as usual, Oliver meets with his Russian mob contact under the pretense of getting into the drug trade. He offers money and the thin police file on The Count, which an old friend at the precinct showed him, in exchange for a meeting with the Vertigo maker. His fellow Russian captain agrees -- as long as he proves he's more than a wealthy brat by killing one of their enemies.
Digg is not happy when Oliver does as asked, putting the guy in a choke hold until he drops limply to the floor. Digg feels a lot better when Oliver carries the body out to the car, drops it into their trunk, and then revives the guy with a touch to his neck.
This leads to this week's flashback, where Oliver languishes in a makeshift cell and confronts a visiting Yao Fei. He feels betrayed and doesn't understand why the assassin protected him, only to turn him over later. He gets his answer when Fyers forces the two of them into a fight to the death, and Yao puts Oliver in that familiar choke hold. Yao makes sure he's the one to push his charge's body over a cliff, so it misses the rocks below and plunges into the rapids. Oliver revives, finds the map Yao slipped into his pocket, and realizes he's been saved after all.
Back in the real world, Digg and Oliver meet with The Count. He lets them know that 56 people died perfecting Vertigo. Just as they're completing the deal, the police show up in force. The Count escapes after injecting Oliver with a heavy dose of the drug, and our hero needs Digg to carry him off to safety.
Unfortunately, Detective Lance is waiting for him at home with Oliver's old friend McKenna Hall. When she confronts him about her seeing him at the drug deal, he quickly makes up a story about trying to get a look at The Count to help out Thea. The police let him off with a warning, but once they're gone, Oliver's mother lets him have it. He realizes her anger is more about him telling Thea the truth about Mr. Queen.
Thea turns up for the fight, and finds out her mother never told her the truth because she wanted to preserve her daughter's good memories of the father who loved her. The two reconcile, which thankfully leads to Thea taking the community service deal for her sentence.
Oliver once again uses Felicity's detective skills to analyze the drug he was injected with -- to track down the water supply it was made with. Still suffering from Vertigo side effects, Arrow ambushes The Count at his factory, destroying the drug-making equipment just as the police again show up on a tip. Lance stops Arrow before he kills The Count with a double dose of his own medicine, but enough of the drug gets into the villain's system to make his future bleak anyway.
Oliver is content that a dangerous drug lord is out of business and his sister is safely being mentored on her probation by Laurel. Then Felicity asks to meet him, and she nervously shares the book of names that Walter gave her before his disappearance. Oliver is clearly disturbed when she mentions that the book belongs to his mother. It seems Thea may have been right after all.
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