A traumatic attack on City Hall triggers painful memories for Rene about his family. Flashbacks reveal how Rene went from simple family man to a hero named Wild Dog. Meanwhile, Oliver must deal with the perpetrator behind the attack and realizes the best way to do so is as Mayor Queen instead of the Green Arrow. Tensions run high in the Arrow bunker.

Oliver faces his biggest challenge yet as mayor. Felicity continues down her dark path with Helix. After Vigilante attacks Oliver while he's acting as the mayor, Diggle leads the team in a mission to stop Vigilante once and for all.

Slade returns and asks Oliver for help in tracking down his son. When they learn Joe has been taken hostage by mercenaries, their mission to save him gets complicated by a terrible revelation that could shatter Slade's hopes of reunion forever. Meanwhile, Vigilante reappears in Star City.

Oliver makes a drastic move in his quest to find Diaz. Like her husband, Felicity pulls out all the stops to get to Diaz. Meanwhile, when arsonists target Rene’s community center, injuring Zoe in the process, the mysterious new Green Arrow swoops in to help save the day. Faced with pressure from the mayor to capture the vigilante, Dinah must decide if following the rules at all costs is the best plan to keep the city safe.

Felicity stands by her recent decisions regarding her family. Meanwhile, Diggle and Lyla continue to look into the Dante painting that Curtis found.