Julius Fair

When a young woman meets a violent death after partying at Verdant, Detective Lance and his partner, Detective Hilton (guest star Roger Cross) inform Oliver and Tommy that she was on the drug Vertigo. Oliver immediately pays a visit to the mental institution where The Count (guest star Seth Gabel) 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 (guest star Celina Jade).

Joss and Harry rebound from their painful break-up in different ways while Calista enacts revenge on a manipulative Luca. Plus, Karen grapples with her feelings.

Karen receives a house call from Alec after her medical procedure proves to be more painful than expected. Plus, Paul's past transgressions continue to haunt April.

Lucy's sexy headmaster, Blair, teaches April about parenting while on a school camping trip. Plus, Joss pushes her new relationship with Harry faster than she should.

April must deal with the past when her mum pays her a visit. Meanwhile, Vivian goes out of town, putting Karen in unexplored territory with Alec.