Less than a week away from the Moment of Truth, Barry and Iris are chatting over lunch at CC Jitters. Barry has been trying, with moderate success, to impress upon Iris the brilliance of Wells' scientific acumen.

"His designs are just so incredible; his work in quantum theory was decades ahead of his time." Barry gestures emphatically.

Apparently Iris is feeling particularly snarky today, though, because she's unwilling to accept that at face value. "Technically, we're now decades into his future; that might only make him a modern man. Or even ten years behind the times…"

Barry huffs out a breath and steals one of her chips. "Fine then, centuries ahead of his time."

Iris hums thoughtfully, allowing him the point. "What exactly does a tachyon generator do? And don't say it 'generates tachyons,'" she adds for good measure.

"Well, tachyons are a big deal because they're faster-than-light particles, and right now, superluminal speeds are purely hypothetical. And, given our understanding of special relativity, such particles could mean time-travel; since time slows down as you approach the speed of light, actually surpassing the speed of light could mean moving backwards through time – there are a couple of different theories on how the resulting paradox could be resolved. And of course, faster-than-light travel is a staple of science fiction space-flight, particularly interstellar travel; there's no other way to go such great distances in a single human lifetime, otherwise, or even several lifetimes."

Iris's brow furrows with thought. "Does it… It doesn't pinch space together, does it?" She pinches her index finger and thumb together on both hands and brings them together. Barry's not sure what she's pantomiming until he makes the connection – Iris didn't read a lot of sci-fi growing up, not as much as he did, but she absolutely loved A Wrinkle in Time and the rest of the books in Madeline L'Engle's 'Time Quartet.' In it, Mrs. Whatsit pinches a piece of string together to explain that they were going to travel faster than light by shortening the distance between the two points, what she called 'tessering.'

"Sort of," he answers. "They're not quite a tesseract, more like… hmm… like if space-time was a porous sponge, then tachyon particles are the bits of sand than trickle through the openings that are already there. They already do exist on a different plane of reality, so calling it a 'generator' is a bit misleading; we'll just finally have the capability of collecting all those loose tachyons that we previously couldn't even observe - "

"Space-time isn't really like a sponge though, is it?"

"Two words: Quantum. Foam."

Iris opens her mouth, gaping for a moment before narrowing her eyes. "I have no idea what that is, but I don't think you're using those words correctly." She waves it off. "Never mind that. What will you do with the particles once you've collected them?"

"Study them." Barry answers promptly.

Iris rolls her eyes. "Fine, don't tell me; keep your nerd dreams all to yourself."

Barry pulls a napkin towards him. "Imagine," he says, using a straw to drip his illustration, "that this dot is everything the human race has ever learned until this moment."

"Does that include twerking?"

Barry ignores her interruption and drips a second circle, as large as the napkin will allow. "That, is everything we could learn from studying tachyons. It's a whole new way of looking at physics! It will literally change the way we think about… everything. And it all begins with this little marvel."

He grins as he pulls up the picture on his phone and turns it around so she can see the mostly-finished tachyon generator.

Iris's smile fades as she looks at the picture, though, and Barry doesn't understand why.

"Is that Cisco?" she asks as if she can hardly believe it.

"Uh, yeah, who else would it be?" Cisco is crouched in the foreground, one arm thrown companionably around the prototype and the other hand throwing up a peace sign. There's also a blur of light that makes Barry particularly pleased with how this photo came out, since it might be a lens flare or it might be Dr. Wells, caught on camera.

"Is he doing okay? Getting enough sleep?" Iris asks intently.

"Ummm… I assume so? He hasn't complained about anything. Iris, what is this all about?" She's starting to freak him out a bit.

She stares at him for a moment as though he's speaking a foreign language. "Barry, look at him."

It takes him a moment, but when he sees it he startles badly, and doesn't understand how he did not notice sooner.

Cisco… looks gaunt. He's got bags under his eyes, and his hair looks lank and unwashed. He's clearly lost weight, though it must have happened so gradually over the past fifteen weeks that Barry never noticed.

"Wow. I… I'll talk to him. I don't know if I could convince him to slow down at this point, though."

They lapse into silence, Barry's earlier enthusiasm considerably dampened.

"Has Dr. Wells told you anything about how he died?" Iris asks delicately.

"Hwuh? No, and I figured it'd be rude to ask. Where's this sudden morbid streak coming from?"

"You know I've been doing research. Well, some things just aren't adding up. Officially, he died of a heart attack – "

"Myocardial infarction," Barry corrects automatically. When he sees Iris's unamused glare, he holds his hands up placatingly.

"But I spoke with Detective Chyre, who had just joined the force at the time – "

"You… what?"

Iris plows on. "And he said that there was something really messed up about that case – that Dr. Wells's heart had been pulverized, but without any visible exterior wounds to his body."

"Why were you talking to Chyre? He retired years ago! Geez, Iris. I just asked for some more information on who Wells was when he was alive; I didn't need a deep background check!"

"You don't get it, Barry! Something is seriously not right about this whole situation. I thought you would be interested – weird cases are right up your alley, aren't they? But instead you keep focusing on all the wrong details."

Barry sighs and runs his hands through his hair. "Look, Iris, I'm sorry if I haven't been altogether with it; we're getting really close to turning on the prototype. It's got us all a little distractible lately."

Iris isn't willing to let it go that easily. "Barry. I want to talk to Wells."

He drops his head and lets it thump against the table. "Iris, we've been over this - I don't have the clearance to bring guests into STAR Labs."

"Then we'll bring him to us. We'll hold a séance."

Gaping, Barry sputters before finding his words. "Wha –Iris, we tried that when we were, like, twelve, and absolutely nothing happened. What makes you think it will work now?"

"Two reasons." Iris counts them off on her fingers. "For one thing, we know for a fact that Wells is still hanging around on this… plane, side of the veil, whatever – so we'll be calling local, not long-distance. He's already a ghost, and we know he's a ghost, so reaching him should be a lot easier than trying to summon someone who may or may not have already crossed over." Holding up a second finger, she continues, "For another thing, I've been doing some research into the occult on the side, and I can now see a number of places where we got it wrong, last time. For instance, the candles do actually have to stay lit. It's kind of important. And it will be better if we can have four people instead of two, for the four cardinal directions."

"Er…uh… okay then. Did you have some people in mind?"

"Wally's back in town on spring break, and he owes me a favor. And maybe one of your friends from STAR Labs wants to help out? It will also help if we had something personal that belonged to the ghost when they were alive, to strengthen the connection of the summoning. Do you know where to find something like that?"

"I'll ask Cisco and Caitlin if either one of them wants to help. As for Wells' stuff, I've been listening to a bunch of his old journal recordings… though Cisco would probably be pretty paranoid about letting those out of the lab; he's very protective of them. But I'm sure I can find something in storage; there's a lot of his stuff that never got cleared out."

"Alright then, it's settled. We'll meet at my place on Friday night."