Oliver:

Oliver asks Stanley if the guards have been rough on him, but he says it's been the exact opposite. Now the guards are against Brick after getting in trouble for the fight club. He escorts Oliver to see his visitor. 

Laurel waits for him and takes a photo of his bruises for her case. She informs him she's working with Felicity. Oliver doesn't trust her motives and tells her to stay away from Felicity. 

Stanley is escorted to pit for allegedly killing an officer. He claims he was set up and begs Oliver to help him. Oliver confronts Brick and his crew, but they don't admit to anything. 

Oliver sneaks his way into the pit to see Stanley. He swears he was nowhere near the guard when he got killed. He says he knows the only person who can help him is the Green Arrow. Oliver tells him to sit tight while he figures it out. 

Oliver goes to the showers where it happened and finds Turner's knife hidden in the brick wall. He gives his intel to the guards, who take Turner to the pit. 

Stanley finds Oliver after he's released and thanks him for helping him. He mentions Oliver finding Turner's blade, which Oliver finds suspicious because he never told Stanley that. 

Stanley claims to have heard it from someone else. 

The Team:

Diaz is holding Anatoly hostage and chastises him for betraying him. He tortures him and tells him, Anatoly will help him destroy Oliver Queen. 

Felicity informs Laurel that Diaz is going after Anatoly. Felicity begs Laurel to stay on Oliver's case even though he's against it. Felicity gets a signal of Diaz's location and her and Laurel head to it. Rene joins them, despite Laurel's protests. 

They find Anatoly and are soon joined by Diggle and Dinah. They have to evacuate quickly because of a bomb Diaz planted. Felicity, Rene, and Laurel have to come clean about what they've been up to so far. 

Diggle agrees to work with the others but not Laurel. Felicity goes after he and pleads with her to continue working on Oliver's case. She promises to call Laurel as soon as they catch Diaz. 

The team uncovers a man named Pyotr Roslov who sold Diaz some high-tech weapons. Felicity coerces Anatoly to help them get into contact with this man and catch Diaz. 

Later, Anatoly pretends to do business with this man and inserts a flash drive in Roslov's computer for Felicity to retrieve data. Diggle wants to provide Anatoly with some help, but Felicity stops him from compromising her mission. Eventually, Diggle goes in but isn't able to protect Anatoly from getting hurt. 

Back at ARGUS headquarters, Felicity and Diggle argue about her actions. Diggle tells her he just hopes she manages to still come out a hero when this Diaz war is over. 

Laurel is at federal court and gives a compelling case to the judge about why Oliver should be released from Slabside. The judge agrees to do an investigation into Slabside but denies the appeal to release Oliver. 

Felicity finds out that Diaz has a hold of two major explosives, so Diggle starts preparations to evacuate Star City. Meanwhile, Felicity checks in on Anatoly and apologizes for almost getting him killed. Anatoly tells Felicity she reminds him of the Oliver he once knew. 

Laurel is about to go all Black Siren on the judge but Dinah manages to stop her. She reminds her what she said in her plea to the judge. Dinah admits she believes Laurel has actually changed and she shouldn't throw away that hard work for nothing. 

Felicity and Curtis uncover Diaz's plan. Diggle decides it's time for the team to get back together on the field. 

While Felicity and Curtis deal with the bombs, Diggle, Dinah and Rene fight with Diaz and The Longbow Hunters. When Diaz gets the upper hand, Green Arrow 2.0 joins the fight. The Longbow Hunters leave Diaz behind as they escape. 

The team watches a news report about the new Green Arrow. Dinah, Rene, and Curtis celebrate the fact that they caught Diaz. Diggle checks in on Felicity, she pretends she's happy but it's clearly not true. 

Laurel visits Oliver again and informs him she lost the case but managed to get the feds to do an investigation into Slabside. She lets him know she's done trying to fit into his box of good or evil. She's about to leave but gets a text from Felicity who tells her they caught Diaz. She turns to tell Oliver but he's already gone. 

Felicity gives Anatoly a new identity to help him escape and he gives her a gun to take care of Diaz. 

Felicity confronts Diaz and he taunts her. She's about to pull the trigger before Laurel walks in. She informs her that they need Diaz alive to help Oliver. She made a deal with the feds, she gives them Diaz and they get Oliver back. 

Flashforward: 

Dinah tells William and Roy that Felicity was murdered. She didn't want to join Dinah's group and instead went underground and started calling herself the calculator. William swears it doesn't matter what she did, he needs to figure out why she left him this signal. 

While William and Zoe are talking, Roy tells Dinah he saw a message inside Oliver's bow when he was on Lian Yu with William, the mark of four. Dinah is worried and doesn't know if they can trust William. 

The four arrive at the place Felicity led William too. A security breach pops up but Roy manages to stop it. They find Felicity's plans to level all of Star City. 

William asks the others to help him get to the bottom of what happened to Felicity. He uncovers that her last call was to someone named Blackstar.