In Star City, Queen Industries CEO Oliver Queen attends to a beneficent party where he meets his rival, Cross Enterprises CEO Marcus Cross, who wants to take over Queen Industries.
Meanwhile, halfway across the city, a mysterious individual breaks into the headquarters of the Checkmate World Security Agency and kills its leader, Colonel Taleb Beni Khalid. The police is tipped off about it and Queen hears about it, leaving the party and adopting the identity the masked crimefighter Green Arrow to investigate.
Upon arriving, he discovers that the assassin used arrows identical to his, framing him for Khalid's murder. Green Arrow is then captured by the police and his secret identity is revealed to the public. He is found guilty of murder and sentenced to life imprisionment at the Supermax Penitentiary for Meta-Human Criminals created by Checkmate, where he is antagonized and tortured by the warden, Amanda Waller.
Queen befriends another inmate, Hartley Rathaway, also know as "Pied Piper", who explains him the rules of the Supermax: Each prisioner has a microchip - the Parallax Device - attached to their arm, which prevents them from using their powers; and each night the location of the cells changes in order to prevent break-outs. They decide to escape together.
Meanwhile, Cross and Queen's best friend, Will Hackett, who betrayed him in order to steal his fortune, discover that Queen needs to be declared dead in order for Cross to buy his company, so they hire the same man that murdered Khalid, the hitman Merlyn, to infiltrate the Supermax and eliminate Queen.
At Supermax, Queen tells Rathway that, five years prior, he fell from his yatch during a tropical storm after embarrasing himself in a party and was stranded on an island for three months, relying only on his skills as an archer to survive before drug dealers who used the island to storage their products arrived on a speedboat which Queen was able to steal after ambushing and arresting them. Unbeknowst to Queen, however, it was Hackett who pushed him off the yatch in a fit of anger and jealousy.
After this, Queen and Rathaway enlist four other inmates to their escape: the shapeshifting Gemini, the teleporter Split, the elemental Cascade and the termomanipulator Icicle. With their help, Queen and Rathaway create a tunnel that'll lead them to freedom. They then have another prisioner, the Tattooed Man, produce a Flash Drive, and storage another prisioner, the living computer virus Djinn, inside. Queen manages to put Djinn inside Supermax's grid, and he disables the Parallax devices, allowing them to escape.
During the escape, Merlyn attacks Queen with a makeshift bow and arrows, but is defeated and captured by Checkmate. A violent inmate, Blockbuster, kills Split during the ensuing riot and takes his place in the escape. However, the group is throw back when they discover that the Supermax is not in the Pacific Ocean as they believed, but in Antarctica. Cascade is killed in the escape, and Waller sends Checkmate after the group.
Checkmate lures the group into a trap, imprisioning them at a Checkmate research center, but they are able to escape. Rathaway is killed in the process, and Blockbuster betrays the others, trying to escape alone. Queen, Gemini and Icicle escape on a Checkmate vehicle just as Waller explodes the facility, killing Blockbuster.
The trio returns to Star City, where Icicle leaves them. Queen and Gemini meet with Hackett, still believing him to be reliable, but he betrays them, and police starts a manhunt on them. Queen retrieves his equipment from a safe house and attacks Hackett at Queen Industries alongside Gemini. Meanwhile, Waller discovers that Merlyn was working for Cross and corners Green Arrow and Gemini in Star City. After a violent confrontation with Hackett, a defeated Queen gives up and is imprisioned again.
Gemini escapes during the fight and recovers evidence of Cross' plan, which she leaks to the press. She then helps Queen trick Hackett into confessing his participation in the conspiracy, and he is arrested by the FBI. Queen is cleared of all charges. Cross commits suicide to escape prison. Queen denounces Waller's inhuman way to treat the Supermax inmates, and she is arrested as well.
Gemini is forced to stay at the newly-reformed Supermax, but Queen manages to reduce her sentence due to her assistance in taking down Waller, Cross and Hackett. He also adopts her 9-year-old daughter Rouge and promises Gemini that she'll have a home at Queen Manor when she's out. He then returns to Star City to continue protecting it as the Green Arrow.
