Barry has been running a lot, trying to get faster so he can defeat Zoom. Caitlin and Harry watch him on the treadmill. He’s not fast enough. Zoom is three or four times faster. Barry leaves to meet Patty.
The Captain of a ship walks onto the dock after weeks at sea. Three weeks ago he found a stowaway, who had 32 knives on him. The stowaway speaks for the first time. He’s waited a long time for this hunt. Suddenly, as if by magic, the stowaway gets his handcuffs off and onto the Captain. The stowaway kills everyone on the dock, reclaims his knives, and leaves.
At the Police Station Barry, Joe, and Patty look at pictures of the crime scene on the dock. Barry explains that there was only one killer. There were pieces of the knife in the victims. Patty thinks it was a metahuman. She and Barry try to act professional, which makes Joe laugh and call them “cute” for not being affectionate in front of him.
After hours, Kendra lets Cisco into Jitters for a date. She made them dinner, and he is very appreciative. They flirt and are about to kiss when the stowaway appears and says he is there for Kendra, who he calls Priestess Chay-ara. Cisco secretly texts Barry for help while standing defensively in front of her. He stands up to the stowaway, who is about to throw a knife at Cisco when The Flash tackles him. The stowaway throws the knife at Cisco, and vanishes while The Flash runs, catching the knife inches from Cisco’s chest. Forgetting himself, Cisco calls Barry by name in front of Kendra.
In S.T.A.R. Labs, the gang tries to get information from Kendra, but she doesn’t know anything about the man. They decide the priority should be to protect her. Barry thinks they should turn to their friends in Star City. Cisco is unsure of Barry’s motives, but Barry points out that they are scientists who have little experience with magic, whereas team Arrow has plenty.
In Star City, Damien Darhk and his ghosts are stealing a bomb from an Argus truck. An arrow hits the ground near them, revealing Green Arrow, Speedy, and Diggle to Darhk, who claims they brought arrows to a gun fight. Green Arrow responds by triggering a magnet in the arrow, which pulls all the guns away from the ghosts.
While the fight commences, Felicity is in the lair, congratulating herself on the success of the magnetic arrow, which was apparently her idea. Green Arrow eventually reminds her she is on an open com link.
Darhk gets his hand on Green Arrow, and is killing him when The Flash speeds past, grabbing and rescuing Green Arrow. Darhk is impressed.
Off to the side, Diggle vomits from motion sickness due to The Flash speeding him away as well. Speedy is surprised to learn that they all know The Flash.
At the lair, Barry is alternately hugged and hit by Felicity, who is happy to see him but angry he didn’t tell her about his recently broken back. Cisco is critical of the lair and says they need copper wiring to fix the power outages which still plague them. Eventually, Kendra is introduced to the gang and Barry speedily sketches the stowaway’s face, which Felicity offers to run through facial recognition. She finds a picture of him from 1975, looking just as young as he does now. Ollie begins to question Kendra, and both Cisco and Barry call him out on his harshness.
Back at S.T.A.R. Labs, Harry tells Caitlin about his five attempts at making a serum for Jay, so increase his speed. They were all failures. Caitlin points out that Harry is an inventor and her medical knowledge could help him. Together, they come up with a new version of the serum.
In Ollie and Felicity’s apartment, Cisco offers to come up with a better nickname for Thea, who insists she likes Speedy. Barry and Felicity catch up with each other, and he tells her about Patty. When Felicity goes to check on her appetizers, Barry and Ollie discuss Barry’s decision to ask for help and Ollie’s newfound happiness.
Cisco secretly admits to Barry that he vibed on Kendra with wings. He doesn’t want her to know he is a metahuman, but thinks his image could be part of why she is being targeted.
Kendra sees something in the window, despite how high up they are. It is the stowaway, who crashes through the window. Barry speeds Ollie his bow and arrow. The stowaway throws several knives, aiming at each person in the group. Barry is fast enough to catch each knife, except for the one which gets him. Arrow shoots repeatedly at the stowaway, who deflects the arrows. At least until Thea joins in with her own bow. Then she and Ollie each get a hit. Ollie calls for Thea to stop, but she shoots a third time, knocking the stowaway off the balcony, lost in her bloodlust. Ollie and Barry look over the edge, but the stowaway is nowhere to be seen.
Back at the lair, Barry and Cisco decide to tell Kendra about Cisco’s ability to vibe, and how he saw her with wings, like a bird. The lights suddenly go out for a second, when they come back Malcolm and several members of the League of Assassins are standing in the lair.
Caitlin and Harry continue to work on the serum at S.T.A.R. Labs. She thinks she has cracked it. Jay Garrick arrives then, summoned by Harry. Jay recognizes the serum, which he called Velocity-6. He is furious that Harry considered this an emergency. Caitlin isn’t sure why Jay is there, but Harry explains that he needs a test subject, someone who already had the speed force inside him. Jay tells Harry that he does not understand the speed force, it is a living thing. Jay warns them against using Velocity-6 on Barry. Harry takes off to get the supplies they need to make the serum.
Malcolm tells the gang that the stowaway’s name is Vandal Savage. The League knows a little about him. Overwhelmed, Kendra walks away. Cisco follows her.
Patty walks to her car, calling Joe regarding the case of the murders on the dock. She sees Harry get into his car. She is shocked to see him alive.
Cisco catches up to Kendra. She does not feel ready to handle all this. Cisco sympathizes, relating to his similar feelings about finding out he is a metahuman. He promises that every day will get more normal. Suddenly, a winged man swoops down, grabs Kendra and flies away with her.
Cisco and Felicity look for Kendra on Felicity’s computers in the lair, while The Flash speeds through Star City and Green Arrow rides his motorcycle, also searching.
The flying man sets Kendra on a rooftop. He also calls her Priestess Chay-ara, and himself Khufu. He recognizes her, but she has no idea who he is, despite a quick flash of memory. He tells Kendra she needs to emerge. The winged man hears Green Arrow’s cycle and flies down to fight him. Green Arrow tries to shoot him down, but the wings deflect the arrows. Khufu knocks the bike out from under Green Arrow.
Cisco tells The Flash where to go, and he joins the fight. Khufu lifts The Flash high into the air and drops him, but Green Arrow saves him. The Flash spins his arms to create a strong wind, which Khufu struggles with. Green Arrow shoots an arrow that ties him up, and The Flash runs around Khufu until he is able to throw lighting at him, impressing Green Arrow.
At S.T.A.R. Labs, Harry finishes Velocity-6. Caitlin thinks they should back off, based on Jay’s warning. Harry thinks Jay is being a coward. As Caitlin walks into the next room, Patty appears. She attempts to arrest Harry, mentioning Dr. McGee recognized him when he robbed Mercury Labs. Harry recognizes Dr. McGee’s name. Patty sees the syringe of Velocity-6 in his hand and thinks it is a gun. She shoots Harry in the chest. Caitlin runs in and stops Patty from calling 911, insisting she call Joe instead.
In the lair, Khufu has been chained up. The gang, minus Kendra, question him. He asks for Chay-ara, saying she is the love of her life. Kendra walks in. He claims they have loved each other for 4,000 years, always being reincarnated and finding each other again. In this life, his name is Carter. And every time they live, they are killed by Vandal Savage. Their three life forces are tethered. Malcolm shows again, telling them that Vandal Savage has left to find a weapon he’s used before, the staff of Horus. Felicity goes to search for museums that might have it.
Joe reaches S.T.A.R. Labs. He sends Patty away and asks Caitlin for Harry’s prognosis. She needs Jay’s help to save Harry.
On a high roof, Carter wants Kendra to jump off so her wings will emerge. Barry, Cisco, and Oliver are unsure, though Ollie is willing to try. Kendra climbs onto the ledge, but Carter pushes her with no warning. Barry speeds down the side of the building to catch her and bring her back up. Ollie asks Barry for a private word. Barry admits that despite his powers, the rules keep changing and it makes him feel powerless. While they talk, Ollie realizes the reason Kendra was drawn to Central City was because the staff must be there, it called her.
Jay arrives at the lab. He asks Caitlin if she can close Harry up if he gets the bullet. She says she can. Joe is confused, so Caitlin explains Jay can take Velocity-6 and use his speed to phase into Harry’s chest and get the bullet. In spite of his earlier reservations, Jay doesn’t hesitate inject himself. It works, he temporarily has his speed again. He phases into Harry’s chest and removes the bullet.
On the roof, Kendra and Cisco talk. She says now she knows why she always felt different. He offers to help her, but she needs to find out the truth alone. She is ready to embrace her destiny.
Green Arrow and The Flash reach the church where the staff is supposed to be, but Vandal Savage is already there and has it. They try to fight him, but Vandal uses the power of the staff to make pews explode.
Kendra knows she’s been holding herself back. She jumps, and her wings emerge.
Vandal Savage senses Kendra, and decides to make quick work of the heroes. He uses the Staff of Horus to make the church explode, but The Flash gets Green Arrow to safety in time.
Kendra lands badly on the roof, and tells Cisco she needs to learn how to use her wings. He names her Hawkgirl.
Harry wakes up. He thanks Jay for saving him. Jay tells him that his speed is gone again, and to never give Barry the serum.
Ollie calls Diggle. Team Arrow needs to come to Central City to help fight Vandal Savage. Carter thinks them all working together is their best chance. They also decide to reach out to Laurel, who is in Central City anyway, visiting her Mom.
At Jitters, Ollie notices a drink named after The Flash and asks Barry about it. A little boy drops a Flash action figure, which also makes Ollie laugh. He watches the boy go to his Mom, and recognizes her as the woman he got pregnant a decade ago.