Barry is a bit freaked out as he tries to help Ollie, he isn’t used to working on a living person. He quickly deduces 4 possible diagnosis, and narrows it down within moments. Ollie’s blood is over clotting, preventing it from flowing. Barry has Diggle begin chest compressions and searches until he finds a box of rat poison, which he uses to thin Ollie’s blood.
In his weakened state, Ollie sees a hallucination of Shado.
Ollie wakes and grabs Barry by the throat. Felicity explains that Barry saved Ollie’s life, but Ollie is furious that Barry now knows his secret identity. Barry promises not to tell, but Ollie continues to rage at Felicity for revealing his secret. Barry stands up for Felicity, but is clearly still star struck by Ollie.
Ollie receives a phone call from Moira, asking him to come home. Ollie tells the group that the serum can now be replicated. Before Ollie can leave, Barry says that Ollie’s attacker touched his neck and that, by removing the oil, Barry might be able to get a fingerprint.
At the Queen home, Moira tells Ollie that Thea is locked in her room and won’t come out. Ollie sees the tree behind his mother and realizes it is Christmastime.
Ollie knocks on Thea’s door, but she does not let them in until he says that Moira is not with him. Thea reveals that Sin and Roy are with her, a green arrow lodged in Roy’s leg. Thea didn’t want Moira to find out that Roy had been that close to the vigilante. Ollie pulls the arrow out and calls Diggle to check on Roy. Then Ollie tells them all to leave Max’s death alone before he walks out, but Thea is not ready to give up.
In the hall, Ollie sees Shado again. He is able to touch her as well. Shado tells him to put down his bow and take off her father’s hood. He says the hood and bow honor her father. She insists that if he does not stop, everyone he knows will die.
Flashback to the sub. Ollie, Shado, and Sara stand around Slade’s body. Ivo and several others with guns arrive and find the serum. They drag Sara, Shado, and Ollie to the land. Sara pleads with Ivo, but he tells Ollie he has 30 seconds to choose which girl lives, otherwise they both die.
Barry hero worships Arrow as he looks around the hideout. Ollie enters and asks Barry for possible side effects from the rat poison. Barry says hallucinations, and excessive sweating. They all realize that Ollie is having hallucinations. Barry offers to test Ollie's blood. Barry asks Ollie why he wears greasepaint instead of a mask. Ollie says he would need a mask that fits his face perfectly or his vision would be hampered, and Barry suggests a material that would allow for that.
At work, Laurel receives a bouquet of flowers from her father. Thea and Sin show up and asks for Laurel’s help. They know Max was not using drugs, because he had donated blood the day he died. They want some information about the donation, if she can help get it.
Ollie stays in the car while Diggle heads to Cyrus’ apartment. At first, he finds nothing more interesting than a book of poetry, but then he is attacked by a masked man with a gun. Diggle manages to jump out the window and get on the fire escape, while Ollie drives around to collect him. They get away.
Felicity calls Quentin, who meets Arrow on a rooftop. Arrow hands over the info they found on Cyrus and warns Quentin that Cyrus is unusually strong. Suddenly, Arrow sees a hallucination of Slade, and quickly leaves.
Flashback to the island. Ollie pleads with Ivo, who mercilessly counts down. After thirty seconds, Ivo points his gun at Sara. Ollie throws himself in front of the gun, and Ivo says that Ollie made his choice, then shoots and kills Shado.
Laurel comes to the Queen mansion to see Thea. Ollie lets her in and they talk about last year’s Christmas party.
Barry performs a chemistry experiment while he waits for the blood test to finish. He recognizes how Felicity feels about Ollie and talks Ollie up to her. Barry turns on a news report about S.T.A.R. Labs and the particle accelerator.
Quentin talks a very reluctant Lucas into helping track Cyrus. Daily overhears and offers to come as well. Daily then immediately calls Sebastian and warns him. Sebastian tells Cyrus to take care of the police.
Ollie asks Felicity and Barry for some privacy, so they go out for burgers. Ollie bounces a tennis ball and is about to shoot it with his bow and arrow when his hallucination of Slade appears again.
Quentin, Lucas, Daily, and a fourth cop follow Cyrus to a large workroom filled with boxes and tools. Cyrus kills the redshirt cop and attacks the others. He is about to kill Quentin when Lucas shoots him. Unaffected by the bullets, Cyrus drops Quentin and kills Lucas.
Slade accuses Ollie of trying to save the city to make up for his father’s sins, when actually it’s Ollie’s sins. He says Ollie is not a hero, friend, or brother. Then the hallucination of Slade attacks and they fight. Slade calls Ollie weak and throws him through the glass display case with his costume inside before vanishing.
When Felicity and Barry get return, Diggle is already there and Ollie is sweeping up the glass. The blood test finally finishes and Barry tells Ollie that his blood is fine, the hallucinations are not because of the rat poison. Felicity learns about Quentin.
In the hospital, Quentin wakes up and sees Laurel at his bedside. He asks about Lucas and she tells him that Lucas is dead. Quentin cries and says he should call Lucas’ wife, but Laurel tells him to rest and says she’ll call.
In the hospital hallways, Laurel sees Daily, arm in a sling. Then Sebastian arrives to check on Laurel and Quentin. As Sebastian hugs Laurel, he and Daily make eye contact and nod.
Arrow visits Quentin, and they both try to take the blame for Lucas’ death. Quentin gives Arrow the one thing he managed to get away with, a key.
In their headquarters (I don’t know what they call it) Ollie tells Diggle about his hallucinations and who Shado and Slade are and that they are dead. Diggle says he also brought some ghosts back from Afghanistan. Ollie asks how Diggle got rid of them, and Diggle says he had to understand what they were trying to tell him.
They (I forget if it was Barry or Felicity) figure out that the key is for a gate in the neighborhood of Crescent Circle and Glade. Felicity tries to talk Ollie out of going after Cyrus, but he goes, promising to come back.
Roy is stealing Max’s file from the blood drive when he is almost caught. As he hides behind a desk, a man (I think a doctor) pours gasoline on the floor outside the office. Roy tackles the man and makes a run for it, but he is knocked out by Cyrus, wearing a mask. Roy wakes up tied to a chair.
The Doctor hands a syringe of the serum to Sebastian, wearing the Brother Blood mask. Roy is injected just as Arrow arrives and shoots Cyrus, who survives being shot with an arrow as easily as he survives being shot with bullets. During the fight, Roy dies and Sebastian calls the test a failure. Arrow is losing the fight when he suddenly sees a hallucination of Tommy, who calls Arrow a hero and says he doesn’t blame him. Renewed, Arrow fights back harder, eventually causing a small explosion that kills Cyrus and destroys the serum. He lets Sebastian escape and starts to give Roy chest compressions. Roy is revived.
Roy wakes up at the Queen mansion, and lies to Thea about what happened.
On TV, Sebastian is announcing his mayoral run. As it airs, Sebastian arrives at an office and confesses to the person he is working for that Arrow destroyed the serum. Sebastian’s boss turns out to be Slade, very much alive and missing one eye. Slade tells Blood that he will get more serum, and to leave Arrow alone. Slade admits that he knows who Arrow is and that he is going to take everyone and everything Arrow loves before putting an arrow through his eye. As he gives this speech, we see several people in Ollie’s life, including Roy whose leg has miraculously healed from the earlier wound.
Flashback to the sub, Slade’s body suddenly revives. He runs after the group, and attacks Ivo’s people. Slade kills one by easily ripping out his heart, starting to realize he is super strong. But he is too late and Shado is dead. Slade cradles Shado and asks what happened. Sara covers for Ollie and says that Ivo shot her without saying why.
Ollie tells Diggle that the ghosts are gone. He then tells both Diggle and Felicity about what happened with Roy, Cyrus, and the mysterious man in the skull mask (Sebastian.) Ollie figured out their plan to create a super strong army. And what is the main purpose of an army? War.
Ollie suddenly realizes that Barry is gone and asks about him. Felicity says he went back to Central City to see the particle accelerator turned on. But he left Ollie a gift.
In rainy Central City, Barry calls Felicity and tells her that while he got back on time, the event was full and he couldn’t get in. He flirts and says if she ever gives up on Ollie, he would be interested in seeing her. Barry goes to his workspace, which has a leaky roof, turns on the news, and reveals a hidden corkboard, covered with articles on Nora’s death. He adds a new one when the power suddenly goes out. In the distance, there is a small mushroom cloud, presumably at S.T.A.R. Labs.
Barry is horrified, and goes to close his huge skylight by pulling on a chain. Something distracts him, and Barry holds the chain and looks around the room. Suddenly, a bolt of lightning goes through the skylight and shoots Barry, who collapses. As he lays unconscious, a charge of red energy rolls through Barry’s face.
Ollie opens Barry’s gift. It is a mask, perfectly made for his face. Ollie puts it on and asks how he looks. Felicity says “Like a hero.”