A girl, Veronica Sparks, is partying at Verdant and taking green and purple pills. Afterward, she goes out into the street and wanders into traffic, dazed and staggering. A car finally hits her and knocks her to the street.
Later, Tommy and Oliver are counting their money when Quentin arrives and tells them about Veronica's death. He knows she was at the club because of the Verdant wristband she was wearing, and he tells the partners that Veronica was using Vertigo. Tommy and Oliver both insist that they don't permit drug use in the club, and Quentin advises them to keep a careful eye out. Once he leaves, Oliver asks Tommy to get him a list of employees so that he can have Felicity compare them to anyone arrested for dealing drugs. When Tommy wonders how Vertigo can still be around when The Hood finished off The Count, Oliver says that he did finish the drug manufacturer off.
Quentin meets with Dr. Webb at the Starling City psychiatric hospital and asks about The Count's condition. Webb assures the detective that The Count has been incapable of doing anything since he received an OD of Vertigo during his last encounter with The Hood. The two men are unaware that Oliver has snuck into the hospital and gone to The Count's cell. The Count rambles on about how he failed the city--The Hood's last words to him--and has made sketches of the vigilante. When Webb and Quentin arrive, Oliver quickly slips out before they can see him. The Count keeps rambling and Quentin leaves, disgusted.
As Oliver fiddles with a bow, Shado and Slade test each other in combat, sparring back and forth. Once Shado gets the upper hand, she warns Oliver not to try and pull the bowstring back for fear the splinters could hurt him. Oliver says that they should be planning to rescue her father and Shado wonders if he can fight. Slade dismissively says that he hasn't been able to teach Oliver anything, and Shado suggests that she train him.
Diggle is visiting his sister-in-law and talking with his nephew, Andy Jr. Once Andy goes to bed, Diggle apologizes to Carly about being distracted, but doesn't mention the newspaper article about Deadshot killing another target. Carly assures her brother-in-law that he can talk about anything, but Diggle gets a text from Oliver before he can respond. He apologizes for the emergency and goes back to the lair, where Oliver and Felicity are watching newscasts about the recent resurgence of Vertigo usage in Starling City. As Oliver tells them that he visited The Count and found out nothing, the news comes up with a report on how the drug lord has escaped the psychiatric hospital. Furious at himself for believing that The Count was honestly deranged, Oliver upsets a table.
Quentin returns to the institute with his partner, Hilton. Webb tells them that The Count was feigning insanity, took him by surprise during an examination, and made his escape. The psychologist warns the detectives not to underestimate The Count. As they leave, Hilton tells Quentin that he checked Veronica's phone log and discovered that she called Tommy just before her death. He's also done some digging and learned that there is $10,000 missing from the club accounts. When Hilton suggests that he should check it out so that Quentin doesn't risk aggravating Laurel, Quentin says that he'll take care of it.
Diggle buys some Vertigo from a drug den and pays them with tagged money. When he returns to the lair, Felicity starts tracking the money, figuring it will eventually end up with The Count. While she works, Diggle has her check on Deadshot. She tracks phone records and learns that the assassin is working through Alberto Garcia. As she gives Diggle a flash drive with the info on Garcia, Felicity wonders if they should tell Oliver, and Diggle insists that it's a personal matter.
Quentin goes to Laurel's apartment and finds the couple having dinner. He asks Tommy about Veronica's call and he says that he gets dozens of calls a night and didn't even notice hers. When Quentin asks about the missing $10,000, Laurel advises Tommy not to say anything further without a lawyer present. Quentin explains that he only came there so that another cop wouldn't and leaves. Disgusted, Tommy tells Laurel that he's not hungry anymore and leaves.
Oliver goes out onto the streets and waits for Felicity to call him when the money has stopped moving.
At the plane, Shadow fills a bowl with water and tells Oliver to slap it over and over again. He doesn't see the point and she tells him that it's the start of his training. Irritated, he slaps the water out of the bowl and Shado tells him to fill it and start again.
Felicity calls Oliver with the location of the money, and he drives off.
A couple of drug dealers drive to the docks in two cars, approach several men on the docks, and offer them Vertigo. Some of them can't pay and the man in the back of the lead car tells the dealers to hand out free sample to those who can't afford it. Oliver arrives and shoots the package out of one dealer's hand. While the head man gets away, the driver of the other car opens fire. Oliver takes him out but is forced to roll out of the way when the lead car circles around and tries to run him over before disappearing into the night.
One of the buyers takes the drug and goes to the Starling City Aquarium and goes up to the glass, talking to the fish. When a security guard approaches him, the addict grabs the man's gun and starts threatening everyone. Felicity hears the report on the scanner and taps into the aquarium's security cameras, while Oliver mixes up an antidote based on the herbs that Yao Fei showed him. When Felicity wonders why he wants to kill the man, Oliver says that Starling City failed the man, not the other way around... and Oliver failed him as well by not killing The Count during their last encounter. As Oliver takes off, he tells Felicity to call Diggle in for backup.
Diggle is out on the streets meeting with an old Army buddy, Lyla. He sees Felicity's call but ignores it, and asks Lyla if her new organization, ARGUS, is looking for Deadshot. He gives her the flash drive and insists that he just wants to help. Lyla isn't convinced but takes the drive and leaves.
Quentin finds Tommy handling a delivery to Verdant and tells him that he's traced the money to a crooked city commissioner. The commissioner didn't inspect the club and Quentin figures that Tommy has something to hide. Tommy invites him to look around as much as he wants once he has a search warrant, and Quentin walks away.
At the aquarium, Oliver arrives and shoots the gun out of the addict's hand. The man flees into the maintenance tunnels and Oliver finally gets ahead of him and punctures a steam pipe. The burst of steam knocks the man down and he goes into cardiac arrest.
When Oliver takes a break from his exercise, Shado meditates and he asks her what Fyers' plan is. She explains that her father was a former general in the Chinese Liberation Army, and Fyers and his superiors are using Yao Fei as the front man to cover their own involvement. Yao Fei was court martialed when he was framed for leading a massacre and sentenced to the island for life. When she tried to find him, Fyers' men eventually captured her and brought her to the island to force Yao Fei to cooperate with them. Shado worries that the island may have changed her father, but Oliver tells her that Yao Fei saved his life and is still a good man. Breaking her meditation, Shado fills the bowl and tells Oliver to begin again.
When Tommy forgets their dinner date, Laurel comes to the club to find him. He apologizes, admitting that he's been distracted, and Laurel assures her boyfriend that she believes him in no matter what her father says. Quentin and his men arrive with a search warrant just as Oliver comes down, and Quentin tells him about the bribe to the commissioner. The detective has checked the city records and confirms that there's a sub-basement. Oliver warns Quentin that he's making a mistake but opens the door to the sub-basement. All of Oliver's equipment has been concealed with boxes and drop cloths, and Tommy opens several boxes to reveal that the room is supposedly used to store liquor. When Quentin wonders why Tommy bribed the inspector, Tommy admits that the ventilation isn't up to code.
Once Quentin leave with his men, Laurel apologizes for her father and assures Tommy that she isn't concerned about the minor bribery. Once she leaves, Tommy turns on Oliver and says that he saw the doubt in his friend's eyes about whether he was selling drugs. Oliver points out that Tommy ran with bad people when they partied together, before he was lost at sea, and Tommy reminds him that he was just the same. Tommy admits that that he doesn't understand Oliver at all and walks away just as Diggle comes in. Angry, Oliver asks his ally where he was during the aquarium shooting. Diggle hesitates at first but finally admits that he was looking for his brother Andy's killer. Oliver tells him that it's not the time for a personal vendetta, but Diggle points out that Oliver is taking the Count's escape personal. Diggle defends his actions, insisting that he can't move on with his life or even look Carly squarely in the face until he brings her husband's killer to justice.
As Oliver goes downstairs to remove the coverings, Felicity comes in and he tells her to check the toxicology report on the dead addict at the aquarium. She confirms that he died of an allergic reaction to chlorpromazine, an anti-psychotic, rather than a drug overdose. Veronica had chlorpromazine in her system as well and Oliver figures that The Count is using it as an additive to his new batch of Vertigo. The only place that The Count could find an anti-depressant like that is at a mental institution, and Oliver figures that The Count faked his escape and never left the hospital.
Later, Oliver enters the institution through the maintenance tunnels and finds The Count sitting in a lab. However, when Oliver approaches the drug lord, he discovers that The Count is comatose and strapped to a chair. Webb's orderly knocks Oliver out from behind and Webb comes in. He kneels and removes the hood, confirming who Oliver really is.
When Oliver wakes up, he discovers that he's trapped to a table. Webb explains that he obtained a sample of Vertigo from a biopsy of The Count's liver. He synthe a new version using the chlorpromazine as one of the ingredients, and then faked The Count's escape when the police started sniffing around. Webb orally administers an overdose of Vertigo to Oliver and the vigilante starts to pass out. However, Oliver has a remote and uses it to trigger an explosive arrowhead in his nearby quiver. When the explosion goes off, it knocks over the table and gives Oliver the chance to loosen his bonds. However, the orderly moves in, ready to kill him. Diggle arrives and attacks the man, while Webb slips out during the confusion. Oliver injects himself with an arrowhead filled with Yao Fei's antidote and vomits up the drug, and then goes after Webb. Meanwhile, Diggle manages to kill the orderly using a defibrillator.
Oliver catches up to Webb and orders him to stop. Confident that Oliver can barely see, Web advances on him, daring him to shoot. Oliver strings three arrows and fires at all of three of the blurry images, hitting the middle one. As Webb collapses, Oliver goes back to the lab and prepares to finish off The Count once and for all. The drug lord has woken up and starts rambling about how a grave is waiting for him. Oliver considers the man and then lowers his bow and tells Diggle that they're finished there.
Later, Oliver comes back to Verdant and checks on Tommy. Tommy assures his partner that they're still turning a profit. He then tells Oliver that he's quitting because Oliver can't see what Tommy has become.
When Slade comes back from hunting, Oliver complains that he wants to do some real training. Shado tells both men a story about how a boy was sent to train with monks. They had him slap water in a barrel for a year, and then invited him to slap the table where his visiting family was sitting. The boy shattered the table in half with a single blow. Shado then gives Oliver the bow he was toying with earlier and invites him to pull it. Much to his and Slade's mutual surprise, Oliver can easily pull it back. Oliver asks Shadow what's next and she tells him that now she'll show him how to shoot it.
Laurel finds her father at a bar, but is happy to see that he's only drinking soda. She wonders why and Quentin says that he didn't feel the need. He's confirmed that Veronica got the Vertigo from a co-worker, not Verdant, and he wonders if he's screwed things up between them. Laurel assures him that he didn't and Quentin admits that his real problem is that he can never let anything go, even when it hurts those close to him. His daughter points out that he's working on that and tells him that people can change.
Diggle talks with Oliver and explains that Felicity gave him Oliver's location at the mental institution. Oliver thanks him for saving him and asks if he's okay with having killed a man. Diggle points out that he's killed before and asks why Oliver didn't kill The Count. Oliver says that he didn't see the point, and that he's changed. However, he figures that not everyone deserves mercy and brings up a photo of Deadshot.
Tommy visits Malcolm and admits that the job at the club isn't working out. He asks for a job in his father's company and Malcolm, smiling rises to embrace Tommy.