Oliver puts Sara Lance up at the manor and soon discovers that she doesn't want to contact her family... both because she would put them in danger, and because she become a killer since the last time they saw her. Meanwhile, the League of Assassins send men to bring Sara back, alive or dead. And Oliver discovers that Laurel will be sitting second chair for his mother's trial.

The Count has a new scheme to turn Starling City's residents into clients by addicting them to a new drug and then selling them Vertigo to cure it. among those stricken are Diggle and DA Donner, who collapses in the middle of presenting his case against Moira.

After covering from a near-fatal drug overdose, Oliver begins hallucinating people from his past. Believing he's a liability, Oliver gives the information he has on Cyrus Gold to Quentin... which results in the deaths of several police officers. Meanwhile, Brother Blood captures Roy and uses him as a test subject for his new serum. In the past on the island, Ivo gives Oliver an impossible choice to make.

In the present, Slade visits Oliver and makes his intentions clear. Five years earlier, Slade, Sara, and Oliver launch their assault on the Amazo, but things go wrong when Slade learns that Oliver was responsible for Shado's death.