Lightning Always Strikes (4) The Flash

17-Boo!

They head back to STAR Labs, and Felicity looks into what the Earth-Xers stole, "Dayton Optical Systems calls it the Prism" she says to them.
"What on Earth, do they need a sub-light generator for?" Harry asks. "It's basically a spectral emitter that"

"Uses quantum entaglement" he and Felicity say together.
"You could also use it to create a stable fusion reaction" Caitlin says.
"Okay, which all means what?" Iris asks and they all look at her, "No, guys, really, I would like to know what you're talking about" she adds.

Felicity looks at Harry, "You go this"
"Well, basically the device they stole can be converted to a neutron bomb" he tells her.
"I take it back" Iris sighs.
"The bottom line is that we have to catch these parallel-earth, goose-steppers" Felicity says.

"Well, this might help" Katrina and Barry come in holding the kryptonite arrow.
"Is that a kryptonite arrow?" Alex asks taking the arrow.
"Yeah" Katrina says to her.

"I know I shouldn't have to ask this question, but I have to ask this question. Oliver didn't shoot Kara, did he?" Felicity asks them.
"Sort of, the other archer and flying woman are Oliver and Kara of Earth-X" Barry tells them all.
"When you said Earth-X was horrible, you might have undersold it" Caitlin says to Harry.

"Wait a minute, how-how could there be another Kara?" Alex asks.
"Well, there are 53 Kara's, just like there are 53 Kryptons and 53 Earths" Harry says.
"You're wrong Harry, because there is not a Kara on our Earth" Katrina says to him.
"Right" he then says to her.
"And the Thawne from our Earth is working with them" Barry tells them all.

"He's an idiot" Harry remarks.
"Okay, if that arrow has not-so-Supergirl's blood on it, we co-" "We could track it using quantum analysis" Harry cuts off Felicity.
"We could" Felicity says to him.

"Hey, guys, I think I might have a quicker way" Alex calls out from the other room, and they all go to see what she discovered. "Theses red blood cells are suffused with shortwave radiation" she explains to them.
"Solar radiation?" Caitlin asks.
"Yeah, incredibly high amounts. Like nothing I've ever seen" she tells them.

"Can you track it?" Barry asks Felicity.
"Well, I once caught a deranged serial killer off his face cream, so..no joke" Felicity says.
"Let's just do it and fast" Barry says to them all.

Alex, Caitlin, Felicity, and Harry were trying to use what Alex had discovered to find the Earth-Xers while Mick just sat on the hospital bed drinking beer. "Maybe tracking her off of face cream would've been easier" Caitlin says as they were not having much luck.
"Supergirl-X's blood is filled with solar radiation, more than it should be- but if I could try to get that to act as a kind of beacon" Harry says to himself.

"Hey, ahem" Mick says getting off the bed, and going up to Caitlin, "How do you do it?" he asks her.
"Do what, Rory?" Caitlin asks him.
"Bring the other you, out of you" he says to her.
Caitlin rolls her eyes, "You don't want to know' she tells him.

"Sure I do" he then says.
"It happens when I am scared or angry" she explains.
"Oh" he says thinking for a moment, "So if I were to, um..BOO!" he shouts trying to scare her and they other girls look at him.
"Nice try" Caitlin says having had no reaction.

Suddenly Harry slaps the desk, "Boom, whatever's going on with Kara-X's blood it's intensifying" he explains to the group.
"Worse for her is better for us" Felicity says turning back around in her chair.
"Better for us for tracking her at least. We should have her location any minute" Caitlin says as they continue their search.

Barry holds on to Katrina as they were in the time vault looking at the footage of Thawne, "I can't believe he's back. I don't know it we'll ever be rid of him" he says to Katrina.
"I know how you are feeling, and how much you are hurting from seeing him again" she says to him.