This week in Arrow, Moira’s back at Queen Consolidated and she’s not receiving the warmest welcome. A super strong burglar has been breaking into different warehouses and medical buildings in Sterling.
A Queen Consolidated warehouse was broken into and had a centrifuge stolen by the super strong burglar. Oliver, Felicity, and Diggle visit the warehouse and a man named Barry Allen shows up from Central City, where he’s an investigator with the police department. In Central they’d been having some similar criminal activity, so he thought he’d get more information about his city in Sterling. Oliver is suspicious, but Felicity is eager to get more information about the burglar.
Together, Felicity and Berry find sugar crystals in the burglar’s footprints. With some investigating, Felicity finds out a local sugar factory recently had a delivery truck stolen.
Sin calls Roy for help - her friend Max has been missing for over a week. Thea insists on joining Roy in helping Sin.
Merlyn shows up to see Moira once again, but this time he wants to see his Thea, his daughter, because she is all he has left.
Just as Felicity and Barry are explaining their findings, Felicity sees a robbery occur at a blood bank.
Arrow goes after the sugar delivery truck full of blood and gets nearly beaten to death by the burglar. Back at Arrow HQ, he tells Felicity and Diggle that he’s seen these kind of people before on the island he had been marooned on. He had destroyed the last of the serum that created these monsters - or so he thought. He managed to get a blood sample from an arrow he tried to put through the burglar’s thigh. Felicity found ketamine in the sample.
In an effort to improve relations between the company and Moira, Oliver hosts a party. Smitten, Felicity invites Barry. The next day, Oliver finds Barry in his lie. He doesn’t work for any police department, nor has there been any incidents like this in Central. Barry’s interest in this is entirely personal. When he was a child, his mother was killed by a mystery strong man who flew like a blur through the house, decimating his childhood. His father was put in jail for the murder of his mother even though Barry did everything he could to convince them his father was innocent. He apologizes and leaves. Felicity reacts really negatively toward Oliver, because what are they doing but lying to everyone they know about who they really are?
Almost no one shows up to the party. Oliver surprises Felicity by reinviting Barry to be her date and welcome him back into the investigation. Roy gets a text message from Sin - it’s important and he’s got to leave. Thea can’t leave with him. She needs to support her mother.
Roy shows up to a taped-off police scene. Max is dead, and there’s blood dripping out of his eyes. Roy takes some quick pictures of his face before getting pushed out of the crime scene. He meets up with Arrow later, hungry for justice of Max’s death. Arrow tells him not to pursue it any further, but Roy tries to run and get a head start. Arrow shoots him through the calf and leaves him in the alley.
Merlyn pays Moira another visit, but this time she’s ready. Merlyn was part of the League of Assassins, an organization of killers lead by Ra’s al Ghul. They follow a strict code of honor which Merlyn has broken. Moira informed Ra’s al Ghul of his betrayal to the League of Assassins. Instead of worrying about his daughter, Thea, Merlyn has to worry about Ra’s al Ghul hunting him down.
Arrow predicts the next target for burglary and confronts one of the strong men. They fight and Arrow is thrown across the room against a box full of hypodermic needles. Two of them end up in his leg, and he’s knocked out.
Hours later Felicity and Diggle show up, bring Arrow back to his lair and call upon Barry to help them revive their friend.

New episodes of Arrow air Wednesdays at 8pm on The CW.