Arrow season 1 episod 19
Watch online episod 19 – "Unfinished Business"
After a girl dies from using a new form of Vertigo, Oliver sets out to interrogate the Count and determine who is dealing drugs in the Glades. Oliver quickly determines the Count has lost his mind from the Vertigo overdose he received from Oliver months prior. When news reports state that the Count escaped the facility shortly after he left, Oliver suspects that the Count was faking his mental illness. Meanwhile, Detective Lance finds loose connections between Tommy and Vertigo, and attempts to uncover the truth, which almost leads him to discovering Oliver’s hideout. Fortunately, Tommy has all of Oliver’s gear stored so that Lance does not find anything. Tommy eventually quits the club after realizing that Oliver did not trust that he had nothing to do with any drug dealing; this leads Tommy to ask his father for a job. Felicity isolates an anti-psychotic compound in the drug, and Oliver realizes that the Count’s psychiatrist is the one really behind the re-emergence of Vertigo. Oliver stops the doctor, and opts not to kill the Count, who truly lost his mind from the Vertigo overdose and was the unwitting scapegoat of the doctor’s actions. Afterward, Oliver decides to help Diggle track down Deadshot, who was responsible for the death of Diggle’s brother. In a flashback, Yao Fei’s daughter, Shado, begins training Oliver to use a bow.