When a has-been boxer is killed, the CSIs must establish which of several life-threatening acts actually killed him.

Vertigo causes Laurel to hallucinate an epic fight that pits her Black Canary against her sister Sara. Meanwhile, Chase surprises Thea and Roy warns Thea to stay away from Malcolm.

With crime at an all time low, Oliver decides to take a break and asks Felicity on a date. However, they’re interrupted when a new drug dealer take the name…