The episode, titled “Vertigo,” is described as follows: Thea is in trouble with the police after she gets caught using a drug called “Vertigo.” Oliver thinks the only way to keep her out of jail is to find the dealer, a man who goes by the name of “The Count” . Oliver turns to McKenna Hall (guest star Janina Gavankar), an old flame and current Vice cop, for help. Meanwhile, Laurel steps in to defend Thea, and Felicity gives Oliver some disturbing news about Moira.
Arrow airs Wednesdays at 8 p.m. ET/PT.
