The team come back after a failed attempt to make Barry faster while Peter was giving Jesse a bit of information to get around her new home when they return. They complain to Barry he they've been at this and they all really need a break.

"And the best way for us to have fun, is for us to go out to the club." Cisco suggests to them. "Am I right, team Spider-Flash?" He asks them and they're all confused on the name.

"You know, Peter's Spider-Man, Barry's Flash. So to not leave anyone out, I combined the names. Let's get turnt!" Cisco explains before leaving.

"In all honesty, he's right. We need a break." Peter says, agreeing with him.

"You know, they're right, and if I'm saying we need a break, then you know it's serious." Caitlin states to Barry.

Barry sees that everyone is tired and deserve a break.

"All right, lets go out tonight. We'll go out tonight." Barry agrees to them.

"I wish I could join you, but I've got the night shift tonight, covering for a friend." May tells them and leaves for work.

-

They go to a dance club in town and take a few drinks.

"I'm really glad you came, Jesse, even though this place is less than ideal." Caitlin tells her over the music.

"Hey, we could've gone to a karaoke bar." Peter suggests and gets angry looks from Caitlin remembering their karaoke night.

Peter quickly stops Jesse form taking a drink. "Sorry, miss underage. None of us plan in getting murdered by your father tonight." Peter states to her.

"Oh, whatever, he's all talk." Jesse informs them when Iris and Wally join up with them.

"What's up, Wally?" Barry asks him.

"Hey, interesting choice of venue." Wally comments on the place.

"Peter picked it." "Barry picked it." "Cisco picked it." The men all say pointing at each other.

"Okay, I picked it. I don't get out much. It had four stars on yelp, so.." Barry explains.

"So who's this?" Jesse asks since none of then have been introduced to Wally yet.

"This is Wally. He's my...foster...step brother? He's my new friend." Barry explains and points to the group. "This is Cisco, Peter, Caitlin, and Jesse." Barry greets them and Jesse leaves to stop the watch from beeping every time she's around Barry.

"Hey, I know I'm practically your only outside of work friend, and your not drunk out of your skull, and that the last time we dance we were interrupted. But you wanna give my club dancing a shot?" Peter asks her.

She thinks and sees a minute alone with Peter is a plus on her and decides to see what he's got.

"Sure." Caitlin agrees and he leads her onto the dance floor.

On the sideline, Cisco and Barry are watching them dance together.

"You think they like each other?" Cisco asks Barry who obviously knows they like each other after the Weather Wizard time travel incident last year.

"I can't tell you how I know, but I already know they like each other." Barry tells Cisco who's actually not as surprised as he expected.

"I ship them." Cisco states to him. "What do you think? SpiderFrost? No, SnowParker. How about SnowSpider?" He asks Barry trying out ship names for the two of them.

Suddenly a flash of lightning comes in and attacks them and starts stealing everyone's purses and money. Peter senses them coming and punches them in the face before they could steal his or Caitlin's money.

Everyone looks at see a female Flash in the bar. She speeds off when everyone saw her and Barry chases after her.

Barry return to the club with the CCPD who all were told the same story. A female Flash stole all their money and someone even snag a picture of the female speedster.

-

Everyone returned to Star labs to figure out where this speedster came from.

"I mean, where did this woman even come from?" Barry asks Peter as they're in the cortex.

"All I know is that woman made 60 smackeroos off Cisco. His words, not mine." Peter states.

"Maybe it's another one of Zoom's leftover henchmen. The only other way to become a speedster is from a particular accelerator explosion." Barry replies and then Peter remembers the Velocity serum that Caitlin has been trying to perfect.

"Actually, Caitlin might know another way." Peter says when said Caitlin storms into the cortex and Cisco close behind, and she seems angry at something.

"Speak of the Snow." Peter says happy to see her, but then notices her mad/upset face. "You okay, Cait? You look like Marilyn Monroe just told you she got a better grade in biochemistry than you."

"So what's this I hear about my Earth-2 doppelgänger?" Caitlin asks them, who just look towards Cisco.

Barry and Peter just shout "Dude!" Since they agreed not to talk about Earth-2.

"I'm sorry, it just slipped out." Cisco explains to them.

"Look, the only way we could find Barry when Zoom kidnapped him, was to convince Killer Frost to help us. And she figured she owed me when I stopped Zoom from killing her, and she...kissed me." Peter says getting odd looks from everyone.

He got a silent "Wow" from Barry as Caitlin looks upset.

"Cait, I can explain." Peter tries explaining everything.

"When were you gonna tell me about this?" Caitlin asks, interrupting him.

"I mean, I didn't see it as anything important. I just passed it as her way of saying thanks. And I knew you'd start freaking out if I told you."

"Wait, why are you making a big deal about this?" Barry cuts in.

"I..I...she's a criminal." Caitlin says while stuttering half of that statement.

"And she saved our lives." Peter defends since he believed she's changed after their visit. "Besides, it's not like I wanted her do it. She just did it out of the blue. And it was no fun afterwards, it felt like I was eating ice cream in a air conditioning room."

Caitlin doesn't say anything after that and Peter thinks of what to say next.

"Look, Cait, when we convinced her to help us find Zoom, she just lost her Ronnie. She was just as broken as you once were, and it felt like we've been doing that for a long time. She might not be you, but she was close enough that I understood her. And you know, I think you're not angry. I think you're scared." Peter tells her and she's not following.

"I think you're afraid one day you're gonna wake up and just become her. And I'm telling you this right now, that's not gonna happen." Peter says while taking her hand. "If there's one thing you have that she doesn't have, its friends. You have Cisco, Barry, Joe, May, Iris...me. Your doppelgänger might've been a criminal, but in the end she made the right choice and saved us. And I will be here for you for if that day ever comes." Peter tells her causing her to smile.

"Thanks." She tells him.

"Now come on, don't we have a evil speedster to catch?" Peter asks and Caitlin realizes what he's saying and remembers what she was going to tell them.

She brings them to a storage space and shows them a serum. "It's called Velocity-9." Caitlin tells them.

"Sexy name, what is it?" Cisco asks her.

"It's basically a speed drug. Harry was working on it while we were in Star City with mr and mrs. Chicken wings." Peter tells them both. "Also it's still too dangerous, and is seriously deadly." He explains why they shouldn't take it.

The alerts start going off and Cisco looks at the monitors. "Bad Flash is back." Cisco tells the heroes.

"Come on, you know the drill." Peter tells Barry.

Barry speeds into his suit and grabs Peter. "We need to get you some sort of transportation soon." Barry tells the hero.

"Like what, a spider buggy? That's just ridiculous." Peter says as they speed off.

"Bad Flash? I'm loosing my touch." Cisco states hearing the name.

The two heroes try catching up with the new speedster, but she's faster than them. She comes in and punches Barry across the street, and Peter was able to get a good look at her this time.

"Eliza Harmon?"

-

Peter and Barry return to Star labs to tell them what he saw and Caitlin pulls her up on the computers.

"When I was designing V-9, I was having trouble formatting the extracellular matrix, so I called a colleague of mine from Mercury labs for some assistance, which in this case is Eliza Harmon." Caitlin explains and that could explain everything.

"So Eliza knows how to make this speed drug?" Peter asks Caitlin since he knows her.

"No, I followed the protocols of information compartmentalization. I only gave her three of the eight components necessary for V-9's structure." Caitlin explains seeing she thought ahead.

"Unless she reverse engineered her own V-9." Harry suggests while drinking coffee.

"Listen, Eliza's a genius, but she isn't like this." Caitlin tries defending, but Peter knows exactly what he saw.

"Well, it's worth taking a look." Joe tells them and they agree.

Peter knows he's the only one who can get close easily. "I can go talk to her, make it look like I'm just going into work." He offers and Joe insists on going with him and they leave.

-

Peter and Joe go to visit her, and see she's working on something.

"Eliza Harmon, burning the midnight oil as always." Peter comments and she turns to him and smiles.

"Hey, Peter." She greets him with a smile.

"Don't you ever take a break?" Peter asks her.

"You know what they say, these thiocyanate ions won't bond themselves." Eliza tells him. "Who's your friend?" She asks referring to Joe.

"Detective Joe West, ma'am." Joe introduces to her.

"Detective? You secretly a cop or something, Peter or is it something you do in your spare time?" Eliza asks him while laughing.

"It's more of a part-time job." Peter mumbles to himself. "Listen, I'm sure you've heard of the speedster wrecking havoc?" He asks her.

"Yeah, some crazy chick speedster. What's that have to do with Mercury labs?" Eliza asks him.

"Caitlin said that she gave you a formula that she asked your help on. We think it's somehow involved in this." Peter tells her.

"How? What was she working on?" Eliza asks Peter, not following.

"I'm not supposed to tell you, but basically it's a enhancement that could lead to something even worse than what happened to dr. Conners." Peter says.

"You mean, worse than turning into a giant lizard and wrecking havoc?" Eliza asks and sees he's serious. "Okay, look, between us, this place is seriously vulnerable. But I kept all my research on lockdown and destroyed what I had when I gave everything back to Caitlin." She explains to them and they see that's all.

"Thanks for your help." Peter says, but on his way out, his senses go off when he passes a containment system and wonders what's in there.

"Okay, no super tingle or anything?" Joe asks him as they leave her labs.

"Exact opposite. And don't call it that again. She's hiding something." Peter tells Joe.

"Okay, what's your plan?" Joe asks him waiting for something useful.

Peter thinks for a minute and remembers some things he's been working on at his lab.

"I have been experimenting with some Spider-drones. They don't work long distances yet, but I can possibly sneak one into her labs see what she does." Peter says and Joe doesn't want to know why he has those.

-

Peter sends one into her lab and watches Eliza for hours at Star labs, and nothing seems to change in her behavior. That is until nightfall and she starts talking to someone else, and is complaining to how she's always mistreated and she keeps yelling at herself, then looks to the container Peter senses warned him about and he notices she has one container of V-9.

Eliza than says that they need to save it for emergencies, but then is convinced to take it now. She takes it and walks out and Peter sees where her next stop is. He runs back to the cortex and sees the team is all there.

"She's coming!" Peter warns them, running in breathless.

"Who's coming?" Barry asks his friend.

"Eliza! She took the V-9!" Peter explains when sparks start flying and a flash of lightning brings Barry into the pipeline and punches Joe across the room and takes his gun. Peter tries fighting her, but she's faster this time and even his senses couldn't find her in time when she shoots his leg.

"What do you want?" Harry asks, seeing nobody left to stop her.

"Where's the V-9, Caity?" Eliza asks Caitlin.

"Eliza, you have to stop this." Caitlin pleads to her.

"Eliza's not here right now. My name's Trajectory." Eliza tells her while Cisco is helping Peter put pressure on the gunshot.

"Why do the crazies always have to name themselves?" Cisco asks Peter who doesn't respond due to the pain in his leg.

"Look, Elisa, V-9 is dangerous, okay? It's killing you." Caitlin tries warning her, but she's not listening.

"You are boring me to death. Have over the V." Eliza tells them and they still don't have anymore, and won't make any more. So to motivate them, she takes Jesse hostage to have them make more of it.

Cisco helps Peter treat his wound while Caitlin and Harry are making the V-9 for her. As soon as they make it, Eliza takes it and takes it and speeds off.

Cisco opens the cell for Barry to get out of the pipeline and he speeds in and sees Peter injured and brings him into the med lab.

-

Caitlin and May patch up Peter's leg and it's not as bad as she thought, just another hour and he'll be okay.

"Peter, Caitlin, I know she's your friend and all, but homegirl has gone cuckoo bird." Cisco tells them as he's picking up the glass.

"And now she's out there with more V-9." Peter says as he sits up from the med-bed.

"What she doesn't know is, I put a micro tracker in the drug. Now we can track her." Caitlin tells them the good news and they activate the tracker.

They see that she's going back and forward on the Central City bridge. "Villains gonna vill." Cisco comments.

"She's creating friction and at that vibration and speed, she could destroy the whole bridge." Harry tells them, and Peter explains he's not gonna be much help with his leg and considering there's nowhere for him to help, it being on a bridge.

-

Barry understands and runs there and starts evacuating the bridge as Trajectory keeps destroying the bridge until it falls apart. Barry sees that if he runs across the water, she'll get away so he needs to jump across the gap.

He gets ready and feels the energy of the Speedforce running through him and runs and leaps over the gap and tackles Trajectory.

"It's over, Eliza." Barry tells her.

"It's never over." Eliza says while holding another canister of V-9.

Barry pleads for her to stop. "Stop doing this to yourself. You don't actually want to hurt anyone. I know you're not a bad person. This is the V-9 in your system. I also know what it feels like to want to be the best. It makes you feel like there's not enough time to accomplish things the right way, but it's a cop-out. And this is killing you." Barry tries reasoning with her.

She thinks for a minute and just takes it. She feels more energy and starts speeding off, but as she runs, her lightning is turning from red to blue.

Barry watches as she runs and starts turning into ash as she keeps going leaving her suit behind.

-

Barry brings the suit to Star labs while they're trying to figure out what happened to her. "So she just evaporated by running too fast?" May asks, not understanding how this works.

"Looks like cellular degeneration. This might be why Jay kept warning about how dangerous it is." Caitlin explains to them.

Peter looks and sees Barry is confused. "Barry, you okay?" He asks Barry.

"It's just before Eliza disappeared, her lightning, it turned blue." Barry says and that gets them more confused.

"Like Zoom's?" Cisco asks him.

"What if V-9 is what turns your lightning blue?" Peter asks Harry. "That could explain why Zoom is much faster than Thawne or Barry."

"If that's true, then that means he's sick, right?" Cisco asks.

Harry puts all the pieces together why he wants to be the fastest.

"He's dying. That's why he wants your speed. He's dying, and he needs a cure." He tells them and that could explain so much about Jay and why he never used his speed around them.

It explains everything about Jay. He never used his speed around any of them, because he didn't want to show them his blue lightning. But it was also killing him.

Every time he fought the Flash or Spider-Man, it was like he was giving it all he's got because it's all he can do. Because sooner or later, he's going to die.

And the only way he can survive is getting the Flash's speed.