Cicada is back and has been going in a killing spree, Cisco's hands are healed and the dampening abilities have given an idea for a metahuman cure that Caitlin is trying to help with.

Sadly, Crystal is not a big fan of that as evidenced by Caitlin's arguing with herself when Peter found her.

"Crystal, seriously? I can't take it anymore!" Caitlin yells.

"Cait, everything...oh." Peter says as he sees she's wearing the device to talk to Crystal. "I may be an only child, but I recognize a sibling spat when I see one. What's going on?"

"Well, I'm trying to help Cisco with his metahuman cure but every time I start working on it, Crystal takes over and messes with my equations." Caitlin says and points to a part of the equation. "Like that. She changed all my heterozygotes into asterisks."

Peter takes a close look at the drawing. "Not to demolish Crystal, but I first thought they were just snowflakes. So she's not on board with the cure, I'm guessing."

"No, and I don't exactly know why." Caitlin says and moves to the computers.

"Have you tried asking her?" Peter wonders, questioning why Crystal doesn't want the cure to be made.

"Yes, but every time we start talking about it, she starts singing Barney's I love you song." Caitlin tells him.

"What about Cisco? He having any luck on his end?" Peter asks.

"Not yet. He went to the Tannhauser off-site some could concentrate. He says it's quieter there." Caitlin says.

"Yeah. Quiet and cold. Not my best strong places." Peter comments even though technically he's dating someone who's kinda quiet and cold.

"So I think if I can isolate the genetic marker that bonds human DNA to Dark matter I can reverse engineer the process and unravel it to create a cure. Except I need meta-DNA that hasn't fully bonded with dark matter yet." Caitlin tells him.

"Because that would be the only time when you would be able to identify the marker in the genome." Peter understands. "So a recently created metahuman."

"In the last eight months or so, ideally. But everyone I can think of has been killed by Cicada." Caitlin says.

"So where would we find someone?" Peter wonders.

-

Harry is with Gideon in the time vault and is still trying to figure out how to translate what Nora's journal is saying, but all he's got is the timeline is malleable line. He gives up for now and heads to the cortex to see how they are at finding Cicada.

"Three metas were killed by Cicada last night." Barry tells them.

"So Cicada's killed almost as many people in the last 12 hours as he has in the last eight months?" Caitlin asks.

"And it doesn't look like he plans on slowing down." Barry adds. "We need to stop him before he hurts anyone else."

"Harry, you have an idea?" Peter asks.

"Not right now." Harry says when the alerts go off. "Dark matter flare has been spotted. It's him."

"Suit up." Barry tells them all and they get to their suits.

-

Cicada is chasing a metahuman who he already drained and was getting ready to kill after cutting her.

"Incoming!" Peter shouts and cicada turns to see Peter coming in swinging and kicking Cicada at the wall.

Crystal came in and froze his hands over so he can't take their powers.

Nora sees the injured metahuman and looks to the others.

"We need Caitlin." Barry tells Crystal who immediately changes to help her.

Cicada starts breaking free of the ice and Peter starts to hold him back when he slams his dagger and sends them all flying.

Cicada walks up to Nora and grabs her.

"No!" Barry yells as cicada stabs her in the back with his dagger.

Crystal and Peter try to stop him, but he gets away.

-

Nora's healing abilities have been slown down because of the Dark Matter and it's affecting her powers.

Luckily, Harry found a connection to all the metahumans.

All the victims have been in prison and Barry pulls up a metahuman arrest log and shows all the people he's killed.

"He's killing in the order of this list." Ralph says.

"The list has addresses, employment information. This is everything a psychopath killer needs to find and kill anyone." Peter says. "But how could he get it?"

"There's only one place." Harry says and they look to Cecile. "CCPD."

Cecile and Barry go to CCPD to tell him about their discovery.

Peter was walking down the halls of Star labs when he heads something shatter and runs to the speed labs and sees Crystal destroying Caitlin's work.

"Okay, Crystal, I respect your right to protest the cure, but this is a bit extreme." Peter tells her gesturing to the broken board and ice around the room.

"Well, maybe Caitlin will get the hint now." Crystal responds.

"What hint?" Peter asks her. "You don't like the cure? We got that, but the reason is unclear." He says when Barry comes in.

"What...?"

"Crystal and Caitlin are having differences." Peter explains while rubbing his head and laying his head on his hand.

"I'll get Caitlin." Crystal says.

"No, actually. I need the two of you." Barry tells them and shows Crystal the list. "We need to get these metahumans somewhere safe before Cicada finds them."

"Oh, and you think they'll listen to me?" Crystal asks. "Well, I do know where to start."

"Okay, if we're going to do this, we're gonna need backup." Peter tells them and has an idea who to bring in. "Barry, I need you to pick up some friends of mine in New York."

-

Peter and Crystal went to find Norvock at Amunett's old hideout.

"Hello, Norvock." Crystal greets him.

"Frost, thank god its you." Norvock says, happy for once to see the heroes.

They explain their situation to him and he looks at the list.

"Some of these guys are bad news, you sure they're worth saving?" Norvock asks.

"Are you?" Peter asks back, getting a bit of a side from Crystal. "Cicada's not going to stop until every meta in this city is dead."

"Damn. You guys are a hot pair." Norvock tells them. "What do you need me to do?"

"We've arranged for everyone to get to witness protection. Federal agents will lead you out of the city, somewhere safe." Crystal explains.

"All right. I'm in, but only if I'm the first one on that transport." Norvock warms.

"Nice of you to look out for your fellow metas." Crystal snarks.

"Then let's hope Flash has our backup," Peter says.

Barry later returns and has their backup.

"Spider-Man. Been a while." Jessica Jones greets him.

"Missed you too, Jessica." Peter says. "Luke, Daredevil."

"Been a while." Matt says with a smile.

"Where's Danny?" Peter asks.

"He and Colline are in China. Looking for Kun Lung." Luke tells him.

"Kun What?" Crystal asks.

"I'll explain later." Peter promises.

They started bringing all the metas together and they're getting restless after a while, especially since they have a criminal past and are surrounded by crime stoppers.

"I'm tired of waiting." One says and walks up to them. "This Cicada, he wants to kill us? I say we kill him first."

"You can't." Barry tells her. "We're your only chance."

"So you keep saying,"

"Look, if you're too dumb to recognize the truth, then you can go, but you're on your own." Barry tells her.

"Enough!" Matt yells at them both. "We're working on getting you out of here as fast and safe as we can. But if you don't want our help, you're free to go. But we're not going to be able to help you."

"He's telling the truth," Norvock says. "I saw Cicada kill Carl Bork. His dagger took away our powers. I ran, Bork fought. That's why I'm here and he's not. So leave if you want, but I'm gonna listen to these guys and stay alive."

With that, everything calmed down and Crystal left to talk to Norvok.

Peter overheard their talk and sees this is probably the only time he'll be able to talk to Crystal without her trying to block him out.

He finds her and pulls off his mask, knowing nobody can see them now.

"Your friends are strange." Crystal comments on Jessica, Luke and Matt.

"Like I tell Frankie, strange is our normal." Peter says. "Norvok seems terrified. Never seen him like that. Even when he had to run from Deadpool. I know how it feels."

"You?" Crystal asks. "You have been afraid?"

"Yeah, constantly." Peter tells her. "You're telling me that you've never felt fear like that?"

"No, why?" Crystal asks.

"Really? Then why are you so worried about Caitlin and the cure?" Peter asks.

While they're talking, Barry returns with the last metahuman.

"Is that everyone?" Ralph asks.

"Everyone except Shawna Baez." Barry says. "Meta that calls herself Peek-A-Boo? Anyone know where to find her?"

"Try the Sundollar on Eighth." A metahuman says and Barry speeds off to find her.

Barry had a run in with Cicada while he was there and had to escape through a breach.

-

At Star labs, Harry tries to ask Nora things about the future, how she knows everything and he ended up being basically threatened by Iris to not continue investigating her.

But he's not going to stop.

Iris might be her mother, but if there's someone hiding something, Harry wants to know what and why she's hiding it. And if it's bad enough for Peter's senses, it's big.

-

Back at the hideout, Peter goes back to Crystal to continue their talk.

"You know you can tell me anything, right?" Peter asks Crystal.

"And?" Crystal asks.

"That's all. I thought I need to remind you that I'm always here to talk if you need to. I understand you're afraid of the cure, weather you care to admit it or not. But some people out there might just want it." Peter tells her.

"I see that, I don't understand why." Crystal says.

"It can save their lives." Peter replies.

"It's not that simple. Because, just like Norvok didn't ask for the snake, Caity didn't ask for me." Crystal tells him. "So if one day she wakes up scared of being a metahuman and decides to take the cure, her powers don't just disappear...I do too. That's what I'm afraid of. 'Cause if I'm gone, and the future comes true and you end up dying, who's going to protect her?"

Matt comes up and knocks on the door using his stick. "Sorry for interrupting, but we're moving out." He tells them and leaves.

"I get why you're scared of that." Peter tells Crystal. "But there's something you don't know. We're not metahumans. We're mutants. Meaning that cure won't work the same on us like it will with everyone else. And when you disappeared, all Cait talked about was how to get you back. So as much as you want to protect her, she wants to protect you just as much. Same goes for me." He says before leaving.

-

They move everyone and hear their transport is here.

"Looks like you had nothing to worry about." Jessica says, seeing no sign of Cicada.

Matt then hears something flying in the air. "You jinxed us, Jessica."

They see Cicada's dagger fly through the air and hits the helicopter and then drains everyone but the few of their powers.

"That's Cicada?" Jessica asks, unimpressed.

"That chopper's not gonna be able to land. Take them out the back and get them on it." Matt tells Barry and Ralph as they leave.

"Let's end this." Jessica says and goes to take a swing at Cicada which he takes and as he tumbles backwards, Luke punches him.

Peter webs his back and sends him flying into some boxes.

"Giving up yet?" Peter asks.

Cicada gets up and throws his dagger at Luke.

Matt tosses his stick that bounces off the ground and smacks the dagger, stopping it from impaling anyone.

Crystal comes over and comes face to face with Cicada.

"We haven't been properly introduced. They used to call me Killer Frost. Let me show you why." Crystal says and creates ice daggers and begins to fight Cicada off as the others stand back as she actually cuts him and gets some blood.

While he's distracted with her, Jessica grabs the heaviest thing she could find and throws it at Cicada who falls in response.

"You can't fight us all off." Luke tells Cicada, waiting for him to surrender.

Cicada slams the ground, sending everyone flying.

As everyone was getting back up, Cicada throws the dagger at Crystal.

"Crystal, duck!" Caitlin tells Crystal and she does jus in time for the dagger to fly past.

On its way back, Crystal freezes it as everyone gets back up.

"Give him hell, guys!" Crystal tells them

Cicada goes to punch Jessica, but she grabbed his hand and flips him into Luke who punches him away.

Peter webs him and pulls him back where Matt is waiting and punches him with his sticks.

"It's over. This. Ends. Now!" Peter says as Cicada gets up, Peter plunges himself forward using a web, punches Cicada, shoots another web behind Cicada, pulls himself and punches Cicada again before doing a flip and sends Cicada flying.

Cicada holds his hand out harder and Crystal drops from exhaustion and before they could finish the job, Cicada escaped.

-

They return to Star labs and Nora has now completely healed.

"Alright, the Feds have processed the metas and they'll be safe." Barry tells them.

"We haven't seen a peak of Cicada's signature anywhere, so he's not using it." Harry informs them.

Crystal scoffs at that. "After the beating Spidey and his amazing friends gave him, ain't no way he's using that dagger anytime soon." She snarks.

Everyone looks to her with that knowledge.

"What?" Crystal asks seeing their looks. "He got what he deserved for messing with my man."

"And I think we all appreciate your help out there, ms. Crystal." Matt tells her. "And I have a feeling that the Spider-Man and Crystal Frost combination is going to be enough to keep this city safe."

"And if you need help, you can always call us again." Luke says.

"Meh, hesitate first." Jessica tells them.

"I like her." Crystal says.

"I thought you two would get along." Peter replies.

"Also, how did Cicada even know where we were going to be?" Jessica asks.

"Only the police knew about it." Harry says when Barry gets a message from Cecile saying she found Cicada's inside man already and he's been put into custody.

"Thanks for your guys' help. Barry can speed you guys back to New York whenever you're ready." Peter tells his friends.

"Happy to help, man." Luke says and they shake hands.

"Well, with that said and done. I need to fix a mistake." Crystal says and turns to Peter and pulls him into a kiss. "That's for your help and talk earlier. By the way...there's a surprise for you if you drop the kid off with your aunt." She says and then strolls out of the cortex.

"Did she just...?" Luke tries figuring out what she just implied.

"Oh, she did." Matt confirms.

Peter spins and faces the others. "Gentlemen, I bid you adu." He says before leaving the labs.

"What just happened?" Ralph asks, confused.

"I think the S.S. Spider-Man is about to hit a iceberg." Cisco jokes.

-

Crystal fixed everything she ruined on Caitlin and kept Cicada's blood on ice so she can help make the cure.

Harry finally found something wrong with the journal and sees someone else has been someone else writing inside her journal, meaning there is someone else behind this.

And now he just needs to figure out who.