Arrow comes across a villain who is bringing guns into The Glades this week.
Isabel Rochev throws a party for Queen Consolidated and Oliver is late.
"The Mayor" wants to create chaos so he can rule the city at the barrel of a gun.
The Mayor is a ruthless and cold killer.
Felicity has a revelation about Black Canary following Laurel and not Oliver.
Oliver, as The Arrow, confronts Black Canary and discovers it is Sara.
Oliver saw Sara about a year after the Gambit went down, but hasn't seen her in about five years.
Diggle and Felicity try to talk Oliver into telling Sara's family that she's alive.
Sara is concerned that Oliver will tell her family she's alive because she thinks they will think poorly of them.
Isabel gets in the way of Oliver sponsoring an event to help rid The Glades of guns.
Laurel goes out to dinner with Adam (the DA) but leaves abruptly.
Laurel gets pulled over for a DUI.
The Mayor gets a crate of stolen military weapons, and Felicity reactivates a beacon that Queen Consolidated created to track them.
Lance is concerned about Laurel's drinking, because he was an alcoholic.
Sara came back because of the earthquake. but Oliver wonders why she is still there.
Lance shows up while Sara is visiting Oliver and Sara listens to their conversation about Laurel having a hard time and what Lance went through after Sara disappeared and then she flees.
Flashback to the prisoner ship. Oliver had been hot and had to remove the bullet and sew himself up to prove he was strong enough to live.
The man on the ship is looking for graves on the island and a look on Oliver's face confirms to him that it is the right island.
Oliver visits the cash for guns event and The Mayor shoots it up, leaving Sin injured.
The Arrow and Black Canary team up to fight The Mayor.
The Arrow tries to get Black Canary to let The Mayor Live, but The Mayor calls her bitch, and she knocks him out cold, but lets him live.
Oliver tells Sara she needs to tell her family she is alive, while Lance attends an AA meeting concerned about Laurel who is at home chasing down pills with wine.
Flashback to the island. Oliver is told his days of screaming are just beginning and he's tossed into a room, a room where Sara is in control.
Brother Blood is revealed.