Hunter could feel it in the Speed Force when his old rival breached to this earth. He should've known it would only be a matter of time before she tracked him down here, since she was the one who'd brought this earth to his attention in the first place. His original plan had just been to steal the speed of this world's flash, since he'd been unsuccessful in stealing it from his own Earth's flash, thanks to her icy partner, or Earth 3's flash, especially since Jesse had released him, but then he'd learned about Jesse Wells' counterpart on this earth and he'd learned about her research. It had seemed that she'd managed to create a similar serum to the one that he'd used to increase his speed and though the formula was still unstable, it was more stable than the one he'd been using. If they combined their researched, he hoped that they could stabilize his deteriorating cells.

But now that his archenemy was here, it was only a matter of time until she tracked him down and he needed to crack this before she did. The good news was that they were close and he was beginning to see how he could finish this without the help of the two scientists, but he needed to confirm his suspicions before he did anything drastic.

"That's it. The final piece of the puzzle. A stabilized formula for the velocity serum." Jesse said in amazement as they took a look at it.

"Perfect. Once we get our hands on this component, we can stabilize the drug." Hunter said.

"It'll take awhile to get our hands on it, considering how rare it is." Caitlin said, but Hunter wouldn't have any of that.

"I recommend that you find it, quickly." Hunter said.

"Excuse me?" Jesse asked.

"You heard me." Hunter said as they began to notice something very familiar appear around him.

"Is that lightning?" Jesse asked, panic beginning to fill her voice while Caitlin prepared to bring Frost out.

"Thank you for giving me what I need." Hunter said.

"What do you mean?" Caitlin asked.

"I was dying, the drug I showed you wasn't as advanced as yours, but that didn't stop me from trying. And while it isn't perfect, this will help me until I find what I need." Hunter said.

"What are you talking about?" Caitlin asked.

"I believe you know my old enemy, The Flash. In fact, you almost look just like her." Hunter said to Jesse, much to her confusion, but to Caitlin, it all started making sense.

"Jesse, get behind me." Caitlin said as she barely managed to keep Frost from coming up in front of her or their, whatever, girlfriend, but she wasn't sure how much longer she could do that or would even try to, since she needed to protect her girlfriend over her secret identity.

"You're Zoom." Caitlin said.

"So, you do know who I am." Hunter said.

"If I'd known that you were that monster we were warned about, I would've destroyed this research myself." Caitlin said.

"I'll give you two choices. Finish the formula." Hunter said.

"And if I refuse?" Caitlin asked and in a blur of blue lightning, Hunter had somehow changed into black version of the Reverse Flash suit, only with a with a full face mask with blue lightning crackling off him, and to Caitlin's horror, he was holding Jesse in one arm and in the other was syringe full of red liquid.

"What is that?" Caitlin asked.

"This is my original version of the velocity serum. Much more lethal. In fact, if the user doesn't already have speed force in them, there's a good chance it will kill them quickly." Zoom said.

"Don't do it Caitlin. I'd rather die than be responsible for this monster being able to terrorize our world. Barry was right. We never should've continued our research." Jesse said, though Caitlin could hear the terror in her voice.

"Then allow me to grant your wish." Zoom said, right as he thrust the syringe into Jesse's neck.

"No." Caitlin shouted as her eyes turned silver and she ice blasted Zoom away from her beloved before rushing over to her.

"Jesse, Jesse stay with me." Caitlin said as she felt Jesse's weakening pulse.

"The only way to save her is to stabilize the drug in her. You know this." Zoom said as Caitlin slid on her ring and tapped it.

"Oh I'll finish the cure alright. But not before I make sure you can never you use it!" Killer Frost shouted as Caitlin disappeared in an icy fog, only to reemerge a second later, in full Killer Frost mode. Due to how difficult it had been for her to comfortably change into her old suit once it was released, so she'd asked him to make her a new one and Cisco had more than jumped at the opportunity. Her new suit was a lunar silver jacket and black leather pants with the former snowflake-like symbol from her old suit, along with black boots, though this one was designed so that she should could use that fog trick to slip in and out of it.

"I wasn't expecting to run into you on this earth." Zoom said.

"You'll never be free of me." Killer Frost shouted as she ice blasted him again, but this time, it was with intent to kill.

So, the Zoom arc is coming to an end and I've got an idea of how I want to end it, but I'm curious on if any of you have any ideas of how you'd like me to deal with Zoom, since now Barry isn't the only one with a personal axe to grind with him, since remember, in this reality, Caitlin doesn't remember what Zoom did to her.