Unfinished Business

"Unfinished Business" is the nineteenth episode of the first season of Arrow. It aired on April 3, 2013.

Synopsis
When a young woman meets a violent death after partying at Verdant, Detective Quentin Lance and his new partner, Detective Lucas Hilton inform Oliver and Tommy that she was on the drug Vertigo. Oliver immediately pays a visit to the mental institution where "The Count" is locked up, but finds he is in no condition to deal drugs. However, when The Count escapes and Starling City is flooded with even more Vertigo-related violence, Oliver and Diggle make it their mission to track him down. After Detective Lance uncovers incriminating evidence against him, Tommy goes to great lengths to clear his name, and the fallout from his actions leads Tommy down a new, unexpected path. In a flashback to the island, Oliver recalls the lessons he learned from Slade and Shado.

Plot
A woman named Veronica Sparks is run over by a car due to an overdose of Vertigo. After a recent party, Quentin comes in to question Oliver and Tommy concerning Veronica. Oliver decides to pay the Count a visit but gets nothing and leaves. Quentin is informed that Veronica was texting someone before her death. And that someone was Tommy. Message: "Can you hook me up?" Tommy says he receives many messages like that and Veronica was only a client.

Meanwhile, Oliver is about to uncover the new Vertigo. Oliver arrives and finds a strapped up Count and is knocked out. He is soon strapped up. The Vertigo dealer reveals he took the original formula and wrapped up something new. He takes the new Vertigo, turns in into liquid form, and does Oliver. But Oliver detonates a bomb arrow, destroying the rest of the Vertigo and finds an antidote and takes it. John comes in and takes down the last two guards. Oliver heads out to finish the dealer off by shooting three arrows at once. The dealer arrogantly taunts Oliver telling him that he'll miss for sure. Oliver fires the arrow. Two miss but one landed straight in the dealer's heart.

Back at the party, Quentin possessed a search warrent to search the building and comes across a door which leads to Arrow's headquarters. Well, sort of to the HQ because when Oliver opens the door, a giant warehouse full of unrenovated stuff is revealed and nothing that Quentin wants is there.

Quentin goes to a bar and Laurel meets him there. Quentin reveals that Veronica got her Vertigo from a co-worker and wants to owe Tommy a apology.

Trivia

 * The title's episode is a reference to Oliver and The Count's past together, though Oliver himself uses it later in the episode when referring to Diggle and Floyd Lawton.
 * The coordinates that Felicity gives Oliver (47.6097°N, 122.3331°W) are actually located within Seattle, Washington.
 * Thea Queen and Moira Queen do not appear in this episode.