Team Arrow is going after Faust with Diggle now officially stepping in as the new Green Arrow. Faust gets surrounded by the other members before Diggle knocks him out.
The team returns to the bunker where Diggle admits that he is still worried someone will eventually notice. Dinah is still not happy that Diggle agreed to take over for Oliver despite his nerve damage.
The next morning William is still amazed that Oliver is really done being the Green Arrow. Later on, Quentin and Oliver are still being interrogated by Agent Watson who isn't giving up on this case yet.
Elsewhere, an assassin named Onyx Adams breaks into Kord Industries to steal some files. Later on, Dinah goes to investigate the crime scene, but she finds out that the intruder left no traces behind.
Dinah helps Felicity and Curtis to connect into the Kord system to see what they can find. Oliver goes to Felicity to get her some food as he had a feeling she was hungry.
Felicity asks how it's going for Oliver being a dad now that he is done as the Emerald Archer. He admits that it's going steady.
Oliver asks Felicity if she can help William with his math problems. She is more than happy to help William out. Curtis gives Felicity a call and reveals that the assassin stole information on a transfer of a dangerous nerve gas.
Green Arrow goes to stop the truck by warning that they are being followed. Team Arrow all get a ride in the truck to keep the drivers safe.
Onyx arrives and shoots Diggle as she tries to steal the gas. The other members are taken down as Onyx and her team uses some form of bright light technology to distract them.
They get into the truck and drives away with the gas. When Wild Dog asks what to do, Diggle chokes before the truck eventually explodes.
The team returns to the bunker where the other members lash out on Diggle. Felicity has found out who the assassin is as they still try to figure out the motives.
Oliver and Quentin are dealing with the anti-vigilante registration. Back at the bunker, Diggle tries to thank Dinah for having his back with the team.
But Dinah admits that she is doing it for the team and not him. Diggle stresses that he is disappointed in himself before Felicity alerts the team about new information.
Oliver checks in on William to see how things are going. Rene goes to see Oliver and explains that he needs to come back.
He goes to the bunker to check in with Diggle and see what's going on. Diggle feels that perhaps this was a mistake to make him the new Green Arrow.
Diggle asks how Oliver managed to do it for so long and Oliver admits that it wasn't easy. Oliver explains to Diggle that he was one of the major reasons why he became the Green Arrow to begin with.
Onyx and her squad are getting ready to strike. William gets help from Felicity with his math problems as he is starting to overcome his struggles.
Later on, the team regroups to go after Onyx and her squad and stop them. Dinah asks Rene if he is willing to go out there again with Diggle in charge.
The baddies are targeting people at a hotel as Team Arrow are on their way. At the hotel, the visitors are being locked inside the hotel but the team is also inside.
Several flash-spheres go off, but Team Arrow had their eyes covered to outsmart the baddies. Onyx, however, unleashes a gas in the hotel which starts to kill the visitors.
Diggle almost chokes again but manages to take action and the team saves the day. The team celebrates their victory back at the bunker with Diggle feeling a bit confident that he can do this.
Curtis and Felicity reveal they have developed an arrow-gun for Diggle. He takes it for a spin and it seems to be helping him quite a lot.
Quentin tells Oliver that Team Arrow did well under Diggle's leadership. Later on, they head to the council of the voting for the anti-vigilante bill as Oliver stops it.
Elsewhere, Agent Watson is watching the news and gets more suspicious of who Oliver is protecting. She puts up a photo of Diggle on the board for people of interest.
Oliver goes to see Felicity who rambles about how great William is. He hands over a set of keys to Felicity so she can enter his apartment.
He admits that Felicity being in both his and Oliver's lives is something he wants. They then kiss.
In a dark alley, someone is buying a form of a drug. It's none other than Diggle who is injecting himself with something that keeps his nerve damage in control.