Kara looks through her notes on the computer, before realizing that she really doesn't want to go back to Earth 2 yet, because what if there is another dimension out there where Krypton survived?

As she mulls this over, she realizes that the interdimensional device is just sitting there on the table. Risking a glance at the other two who are still arguing over whether Alex should travel to Earth 2.

"I understand why you think you should come with us, I really do," Cisco retorts, trying to find a way to persuade the agent to stay here. "But this is not a pleasant trip for humans, trust me, it is hella uncomfortable."

"I don't care. Look I trust you to keep me safe. What I don't trust is her," Alex blurts out the admission and then closes her eyes. She can't take it back and she knows that there's no way the Kryptonian didn't hear her.

Kara stares at them both long and hard before looking at the breach device in her hand. "Since we're being honest," she retorts, "You have good instincts Alex," And then she pushes the button, the portal opens and she steps through it without hesitation.

"What the hell?" Alex bellows. "Cisco, can you track her?" She turns to face him just as another portal opens and he's gone with just a small salute.

The brunette just shakes her head. "Unbelievable," she mutters before tapping her earpiece. "Winn, they're gone. Kara took off into the breach and Cisco took off after her," Alex informs the tech guy.

"Whoa, yeah the tachyone particle reader is off the charts right now. Sit tight and I'll be right over, I might have a way for us to track them," Winn replies excitedly.

On Earth two, Alex and Kara are comparing notes about their sisters when suddenly a portal opens up and Cisco stumbles into the room.

"Cisco!" Kara exclaims. "Rao, it's so good to see you."

"Kara? Whew, okay so at least I found you," the shaggy haired scientist remarks. "Oh, hi. I'm Cisco Ramon and you must be Alex Danvers," he says turning to the agent.

"How do you know... Oh right, if you're from the other Earth, then where's my sister?" Alex inquires.

"About that, so I was just on Earth 38 with her and we were about to return here when the other Alex sort of upset her and she took off," Cisco carefully explains.

"She took off, as in used that device again and could be on infinite earths, took off?" Cat Grant asks striding over to him.

"Cat calm down, he tracked her to that Earth. He can track her again," Alex points out calmly.

"If that's true, then why is he here, when she isn't?" Cat questions impatiently.

"I-I wanted to let you know what was happening and also, uh, Kara, would you come with me. I need to consult with my team?" Cisco asks his friend.

"Of course," Kara replies quickly. "Let's go," she adds.

"Not so fast, I'm coming with you too," Alex states.

"Alex, stay here. I promise you, I'll bring her back," Kara says earnestly.

"Look, no offense, but I know my sister better than you and I can talk to her," Alex points out.

"No offense, but I think that this will take another Kryptonian, neither of us can keep up with her like Kara can," Cisco counters and with that he opens up the portal and the two of them disappear before Cat and Alex can respond.

The portal opens and they're back at S.T.A.R Labs.

"Hey, Kara!" Barry exclaims opening up his arms for a hug.

"Barry," Kara says heavily, falling into his embrace.

"I get the feeling that this isn't just a visit," Barry says pulling back a little to look at the alien's face.

"Yeah, so her doppelganger from Earth 2 has taken the interdimensional device and we don't know exactly where she is," Cisco exclaims as he sits down at his command console and begins working on tracking her.

"How did that happen? You programmed it to only go between this earth and hers," Barry blurts out.

"Well, I programmed it to only read two frequencies and that should have restricted it to Earth 1 and Earth 38," Cisco replies.

"Uh guys, on Earth 2 they told me that the device responded to me and it would take me wherever I wanted to go," Kara informs them.

Caitlin exchanges a look with Cisco before crossing the room and picking up a scanning device. "If that's true then the energy in your bio-cellular matrix is overriding the frequency limitations of the device," Caitlyn explains as she holds up the scanner, silently asking the alien for permission to use it.

Kara nods to her to go ahead, as she considers what the scientist has said. "Are you saying that I can travel dimensions without the device?"

Caitlyn purses her lips as she looks over the scanner's readout and then shows it to Cisco.

"Your body's electromagnetic force field is stronger than it was the last time you were here," Cisco exclaims incredulously.

Caitlyn and Cisco go back to the command console and look over a few things.

"Maybe there is something on Earth 2 that's enhancing her powers," Cisco suggests.

"Cisco, her levels are almost higher than yours," Caitlyn points out.

"Uh wow, that means that she doesn't need the device to travel and neither does her doppelganger," Cisco counters. "But if she doesn't know that and she's still using the device then we can track her by tachyone particles," the tech wizard says turning back to his computer.

"Kara, you know her better than we do, where do you think she would have gone next?" Barry asks.

Kara arcs an eyebrow as she considers the situation. "I'm not sure. I mean, if it was me, I'd want to find an Earth where I didn't exist, because then maybe it would mean that Krypton is still there."

"According to this interdimensional scan, there was an increase in tachyone particles on Earth 3 in the last half hour," Cisco says excitedly, jumping up and going over to Kara.

"Kara, you don't have to do this. We can take you home and Cisco and I can track your doppelganger," Barry offers.

"I want to do it Barry, I promised her sister that I would bring her home," Kara explains.

"Okay, well good luck to you guys and let me know if you need help," Barry replies worriedly.

On Earth 2, Alex and Cat are still arguing over why Kara would have taken off again when another portal opens and two more people stumble out of it.

The brunette is about to pull her gun when she realizes that she could be staring into a mirror. "What the...?" She blurts out.

"Uh, wow, y-you're me or m-maybe I'm you," the other woman exclaims.

"Trippy," Winn blurts out. "Hey Ms Grant," he adds noticing the other woman.

"Winslow Schott?" Cat queries looking at the young man.

"Yes, you know who I am!" He says happily turning to Alex. "Woo, hoo! I'm on this earth too!"

A moment later he finds himself face down with a knee in his back.

"Toyman Junior, I've finally got you!" Alex says triumphantly.

"Wait, he's not who you think he is, he's from the other earth and he works with me at the DEO, he's an agent!" The other Alex explains quickly.

"Why should I believe you?" Alex from Earth 2 asks.

"Because we think that we know where your sister is and Agent Schott is the only one who can help us get there," Alex informs her.

The agent considers this for a moment and then releases her hold on him and helps him up to his feet. "This better be true," she says pushing him back towards the wall with one finger. "Because there are at least six different and quite painful ways that I can hurt you with just my index finger, do not test me," she growls at him.

"Down girl," Cat says laying a hand on Alex's shoulder. "Obviously this is the doppelganger from the other Earth, look at his clothes, Toyman Junior wouldn't be caught dead in a cardigan," she adds.

"Uh thanks?" Winn mumbles as he rubs the spot where she poked him hard in the chest.

Cat shrugs and steps away. "Is this true that you have a way to track her?" She asks them.

"Yeah, I have a portable Tachyone detector, that's why we're here," Winn blurts out.

"Well, Cisco was just here and he took your Kara with him," Alex from Earth 2 informs them. "You're tracking him not my sister," she adds sharply.

"Look, he's tracking your sister, so if we track him eventually we'll get to her," Alex from Earth 38 points out.

"It looks like there's a really high reading of Tachyone particles from Earth 1, so Cisco and Kara must have just left STAR Labs," Winn says showing the reading to his Alex.

"Okay, then let's get going," Alex says grabbing his arm.

"Wait, I'm coming with you," the other Alex says grabbing his other arm.

"Uh, guys this is a terrible idea," Winn grumbles.

"Just push the damn button Winn!" They both shout.