While Oliver tends to the Canary's wounds, he tries to get her to talk about where she came from but she refuses. However, after Oliver and Canary are attacked at the Queen mansion by a trained killer from the League of Assassins, she confesses to how she's connected with the nefarious group. Meanwhile with Moira facing multiple counts of murder and conspiracy for her part in the destruction of The Glades, the Assistant District Attorney offers her a choice - plead guilty now and avoid the death penalty or take your chances in court. Thea begs her mother to fight for her life but Moira seems resolute about taking the offer. Meanwhile, Oliver is furious with Laurel for joining the prosecution's team on his mother's case.

Oliver is concerned when a mysterious illness sweeps the city, infecting hundreds of people, including Diggle. Oliver discovers Vertigo in Diggle's blood and realizes The Count has broken out of prison and is once again distributing his drug. Meanwhile, Moira goes on trial for her participation in the Undertaking. ADA Adam Donner collapses in court with Vertigo symptoms so Laurel must step in and try the case against Moira. Oliver is torn between standing by his family during the trial and catching The Count. However, things change when Felicity follows a lead and walks straight into a trap set by The Count.

After a fight with Cyrus Gold, aka the Acolyte, Oliver is drugged and left for dead. Determined to cure him, Felicity makes a risky decision. The cure causes Oliver to hallucinate, and what he sees forces him to confront his past. Meanwhile, Barry Allen continues to help Felicity, and their connection grows stronger. The Arrow asks Quentin to look into Gold, but when the stakeout on Gold goes bad, someone is killed. Roy is captured and tortured by Brother Blood.

Oliver is shocked when he learns that Slade has come to Starling City. Back on the island, as Oliver, Slade and Sara prepare to take over the freighter from Ivo, Sara pulls Oliver aside and tells him he needs to kill Ivo to prevent him from telling Slade what happened with Shado. Oliver feels immense guilt over the situation but realizes Slade's growing rage from the Mirakuru makes him unpredictable and he could turn on his friends if he thinks Oliver is to blame. Oliver agrees to kill Ivo and the battle begins.