The series follows Oliver Queen , billionaire playboy of Starling City, who spends five years shipwrecked on a mysterious island. Upon his return to Starling City, he is reunited with his mother, Moira Queen , his sister, Thea Queen , and his friend, Tommy Merlyn . The first season focuses on Oliver rekindling his relationships and spending his nights hunting down and sometimes killing wealthy criminals as a hooded vigilante. He uncovers a conspiracy to destroy "The Glades", a poorer section of the city that has become overridden with crime. John Diggle and Felicity Smoak assist Oliver in his crusade. Oliver also reconnects with ex-girlfriend, Laurel Lance , who is still angry over his role in her sister's presumed death. The first season also features flashbacks to Oliver's time on the island, and how it changed him; this continues in subsequent seasons.
In season two, Oliver has vowed to stop crime without killing criminals, and comes under attack from Slade Wilson, a man from Oliver's time on the island who resurfaces with a vendetta against him. Oliver must also contend with outside forces attempting to take over Queen Consolidated, guilt from decisions he made in the past, and secrets harbored by his family and friends. Oliver grows to accept aspiring vigilante Roy Harper as his protégé, and begins to receive assistance from Laurel's father, Officer Quentin Lance . Oliver also gains another ally; a mysterious woman in black, who is eventually revealed to be Laurel's sister, Sara Lance, who had survived her ordeal at sea years prior.
In season three, Arrow has become a public hero in Starling City following Slade Wilson's defeat. Queen Consolidated is sold to wealthy businessman, scientist, and aspiring hero Ray Palmer . Oliver struggles to bring his family back together, an old enemy returns, and Oliver becomes embroiled into a conflict with Ra's al Ghul . After a rocky start, Laurel sets out to follow in Sara's footsteps as the Black Canary. John Diggle struggles with his new role as a family man, as Oliver no longer wants him in the field after the birth of John's daughter, while Felicity Smoak begins a new career as Vice President of Palmer Technologies (formerly Queen Consolidated).