"Gideon, show me the timeline from the year 2030." Bar demands.

"Certainly Mr. Allen." Gideon greets, and that's when she shows him the future. There were less casualties now, but the uprising still happens. Okay, so I'm on the right track.

"Thank you, Gideon, please go back to the 2024 article." Bar orders.
"Of course Mr. Allen." Gideon greets, changing to the 2024 article. Slowly, Bar walks out of the time vault, joining the rest of the team.

"You know what I think would cheer you up Bar?" Barry asks.

"What?" Bar asks. The only thing that would cheer me up, is to erase the war ridden future that I came from.

"You getting to see Captain Singh again. You could go down to the CCPD as me for the day, what do you say?" Barry offers.

"That would cheer me up. Thanks Barry." Bar smiles. That was the first time Barry had seen Bar smile since he got here. Maybe war does that to a person?

Slowly, Bar changes into some of Barry's clothes, and that's when he races down to the precinct. When Bar gets to the precinct, memories of the uprising came to his mind.

The precinct was a prime meeting spot for the humans, and any metahuman that was caught on the premises was shot without warning, Instinctively, Bar had his guard up as he walks into the precinct.

Instinctively, he reaches for his gun that isn't there. Stop it, you're not in 2033 anymore, it's 2017, there is no uprising, you're safe. He scolds himself. Finally, he walks inside, and that's when he takes a moment to just breathe. Where was his lab again? It had been sixteen years since 2017, so his memory of the precinct from before the uprising was vague at this point.

Bar couldn't remember at this point, so he decided to wait for someone to come talk to him. Bar was standing there for ten minutes, before David walks in, and that's when he notices him. Why's Barry just standing there? Maybe I should go talk to him, he seems confused.

Slowly, David walks over to Bar, and that's when he stops to take the time to look at the kid.

This Barry was paler, older. The once youthful glow was gone from his eyes, leaving behind a hardened, lifeless expression. David had recognized this hardened expression in some of the ex-veterans that worked at the precinct, but seeing this expression in Allen broke his heart.

"Allen?" David asks, still processing this new, older version of Barry.

"It's good to see you Captain." Bar smiles. Slowly, David invites Bar to his office, closing the door as they both sat down.

"What's going on Allen?" David asks.

"Please, call me Bar. I hate being called Allen." Bar pleads.

"Okay, Bar. What's going on? It's pretty obvious that you're not my Barry, so who are you?" David asks.

"In the year 2030, your Barry's blood is stolen, and is used to create a street drug called The Speedster's Paradise. This drug can turn anyone into a speedster, much like The Flash. The new speedsters went mad with power, and there was an uprising. Metahumans and humans were at war with each other, which eventually leads to the destruction of Central City. I stayed in what was left of Central City until the year 2033. It was then that I used my speed to run back here, to 2017, to stop the uprising." Bar explains. David's eyes widened at that statement.

"Are you saying that you… my Barry are The Flash?" He asks, lowering his voice.

"Yes. Don't tell your Barry that you know, though. If I know my younger self, he'll freak out, and that's what we don't want to happen. Let him tell you in his own time." Bar demands.

"So, I have to ask. How old are you anyway Bar?" David asks.

"Forty-four." Bar answers simply.

"F-Forty-four? But you still look so young!" David stammers.

"One of the curses of the speed force is slow aging. Which is pretty ironic if you think about it. Wouldn't someone with the speed force age faster? That's what I would assume anyway." Bar explains.

"So, where is Barry anyway?" David asks.

"He's home. He decided to let me come down here for the day. Just so you know, I'm probably going to be incompetent at this, it's been sixteen years since I've had a day job." Bar chuckles.

"Well, I'll leave you to that." David mutters as Bar walks down to the lab after Julian shows him the way. When Bar gets in the lab, suddenly he was back in 2030. Bar was strapped to a cold, metal table. The room was freezing, and the restraints were speedster proof. Alchemy was staring back at him, drawing blood from his arm.

"Why are you doing this, Julian?" Bar groans.

"Because you killed Caitlin Snow, Allen." Alchemy growls, injecting Bar with the Speedster's Paradise. When Alchemy injects him with the drug, Bar starts screaming at the top of his lungs, thrashing against the restraints.

When Bar gripped the beaker, he squeezed it, gripping it as hard as he could. Eventually the glass breaks, slicing through his hand. Julian was startled by the sound of glass breaking, and that's when he looked over towards Bar. The glass was embedded in his hand, and it was bleeding.

"Holy shit Bar! Don't move!" Julian shrieks, running over to the medical supplies as he tries to tend to Bar's hand. When Julian touches Bar's hand, Bar starts to panic, and that's when he punches him as hard as he can, speeding away from him.

"Don't fucking touch me you piece of shit!" Bar growls, his mind back in 2030 when Alchemy had tortured him. Julian screams in pain as he was thrown against the chemical shelf, and that's when Bar snaps out of the memory.

"Oh fuck! Julian I'm so sorry! I'm sorry man! Shit!" Bar panics, running over to him. It made Bar sick that he had hurt Julian, and now he was badly injured, because of him. Sighing, he rushes him to the hospital, and that's when he races down to Star Labs, hoping to find a way to dampen his powers.

A/N: To clarify, Future Alchemy's mind was corrupted by The Speedster's Paradise.
He blames Bar for "Caitlin Snow's death" after she becomes Killer Frost in 3x18. Caitlin has been gone since Bar's timeline in 2017 when she becomes Killer Frost. When Bar ran back in time, 3x18 hasn't happened yet, so Caitlin hasn't become Killer Frost for Barry in his version of 2017.
I know, it's confusing. Basically, Bar's timeline was altered in 2017 when Caitlin becomes Killer Frost. So, Bar is from a different timeline than Barry and Team Flash.