Following Oliver’s shocking decision to turn himself over to the FBI and reveal his identity as the Green Arrow to the public, Oliver has spent the past five months in Slabside Maximum Security Prison. Determined to keep a low profile to shorten his sentence for the sake of his family, Oliver is tested when he runs into old foes. Meanwhile, Diggle and Dinah have taken on new jobs and left their costumes behind but not everyone is following suit. With her focus on William, Felicity tries to start over but when someone from her past resurfaces, things become complicated.

In order to track down Diaz from inside prison, Oliver realizes that will require aligning with an old enemy. Meanwhile, in Star City, Felicity’s attempts to root out Diaz are thwarted by Diggle, whose allegiance to ARGUS now requires him to keep civilians like her on the outs. Realizing that she can no longer rely on her old team or old methods, a clear-eyed Felicity resolves to find a new way to go after Diaz.

Still in prison, Oliver faces his biggest challenge yet. Meanwhile, Felicity gets an intriguing offer, and Diggle asks Curtis to go undercover for ARGUS.

Felicity learns something new about Oliver that shocks her. Meanwhile, Diggle asks Curtis to go undercover for ARGUS. Dinah works with an unlikely ally.

Slabside becomes even more dangerous after a guard is murdered and everyone is a suspect. Felicity enlists help from a surprising source in her pursuit of Diaz, and Laurel flexes her muscles as the District Attorney.