The Simplest Mistake

By TheLostMaximoff

Disclaimer: I don't own these characters. This is my idea for how the season could end, and also my attempt to process a lot of recent sadness. R/R.

Barry Allen doesn't like to think about how many funerals he's been to in his life. He doesn't like to think about how many times he's stood at someone's grave and promised them what he can't deliver. It started with his mother, because everything did. He promised her justice even though he was barely old enough to understand that concept. Even now, he doesn't think he has a very firm grasp on it. The tradition continued with his father and he promised the same thing. Now Barry finds himself at the grave of his best friend and all he can think is how hollow his thoughts are. He could repeat the same lines over and over again but they have lost most of their meaning. How is he supposed to get justice for his dead friend when the culprit is another of his friends? How is he supposed to believe that the universe is still a fair place when he's the one who helped make it so unfair?

It's been a week since Cisco died helping Barry battle Savitar. The emotional wounds are still fresh and bleeding. Barry knows his body can heal fast but not his spirit. He would love to tell himself that Cisco died at Savitar's hand but the truth is more painful to admit. Cisco may have died a hero but Savitar wasn't the one that cut him down. That dubious honor went to someone else. Barry feels his fists clench in frustration at the thought of how Cisco died. He can't help but blame himself for all of this. It was his terrible decision that drove a wedge between himself, Caitlin, and Cisco. They tried the best they could to patch things up but it wasn't enough. He knows that he's lost both of them now and he's the one responsible. He's the one who set all three of them onto this collision course and now he has reaped what was sown. He curses himself for that one moment of weakness that made him think he could remake the universe into his own image. All it took was one simple mistake, one lapse in judgment, to alter the trajectory of all three of their lives.

"I don't even know what I could say," says Barry as he stares at the headstone. "You deserved better than me. I'm sorry that I let you and Caitlin down. I know that's not enough but I don't think I have anything left."

The temperature drops to an unseasonable level and Barry feels his fists clench even harder. He doesn't know what's going to happen when he finally turns to face her. He feels like he's living in a nightmare and there's no way he can wake up. He can't believe that this feels worse than when his father died. He can't believe that he could feel even more broken. For a moment, he thinks about doing for Cisco what he tried to do for his mother. He thinks about what it would be like if he was the one in the ground. It would be a fitting punishment for bringing about the destruction of his two best friends. It should have been him instead of Cisco.

"Sorry I didn't make it to the funeral. I didn't feel like I would be very welcome there."

Barry turns to face the living ghost that used to be Caitlin Snow. He thinks that "ghost" is a good word to describe her now. Her hair is completely white, her lips blue from the cold inside of her, and her skin so pale he swears she's dead as well. He watches the wisps of white smoke curl from her lips, twisting and spiraling into the sky. There's no real expression on her face save for a hollow gaze that Barry thinks might just tear a hole through him.

"Don't do this here, Cait," he tells her. "Just let me say goodbye to him."

"Here's as good a spot as any," decides Killer Frost, the icy vapor from her hands intensifying. "Today's a good day for one of us to die, don't you think?"

"You think that's what's going to happen? You think I'm going to kill you?" Barry keeps searching her face for some glimmer of hope that the girl he cared so much for is inside this monster.

"A girl can dream, can't she?" Killer Frost moves towards him slowly, her gaze never wavering. "I know you don't have the stomach for that, at least not when it came to villains. The people you love on the other hand, well that's a different story."

"I'm not the reason Cisco's dead, Caitlin. That one's on you."

Killer Frost grits her teeth so hard she thinks they might crack. There's something stirring inside the icy cavern where her heart once was. Bad memories flicker behind her eyes. She's not sure what she is right now. She's stuck somewhere between Killer Frost and Caitlin Snow and they're both in so much pain. She remembers how much she enjoyed betraying her friends but also how much it hurt. She remembers the final battle. She never wanted to hurt Cisco. He wasn't the reason why she was so screwed up. Her anger was always towards Barry. So she decided to expel that anger in a volley of ice shards that would cut Barry to ribbons. Just like always, Cisco got in the way. Brave, foolish, stupid Cisco didn't stand a chance. Killer Frost feels herself trying to turn back into Caitlin. Caitlin remembers crying as she held her friend's crumpled body in her arms. In that moment, she wanted to die. Killer Frost kept both of them alive but neither of them knows why. Maybe because the moment to die wasn't then. Maybe this is the right moment now.

"Don't you think I know that? It should've been you, Barry. You deserved it so much more than he did."

"No argument here."

Killer Frost looks at this man that Caitlin Snow used to admire so much. Caitlin loved Barry deep down. She never admitted it but, then again, she was never very good with her feelings. Maybe if she was then she would have told Cisco that she loved him even more. Killer Frost feels the echoes of those emotions. She feels the pain, the sorrow, the regret, and the love. She feels herself slipping back into the darkness so that Caitlin can grieve. Caitlin's so very good at that and Killer Frost thinks she should at least have a chance to do it.

"I can't do this, Barry," says Caitlin and she can see his heart breaking at the realization that it's her talking now. "I can't lose someone I love again. I've done it too many times and I don't . . . there's nothing left, Barry. I don't have anything left to lose."

"Cait, you have to come back to STAR Labs. You have to let me help you."

"You wanna help me, Flash?" Killer Frost twists her lips into a cruel smirk. "Fine, I have a favor to ask of you anyway. One last favor for your old pal Caitlin. Before you give me an answer though, I want you to think really hard about it. I know you're not used to thinking about the consequences of your actions but we did agree that it's good to try new things."

"Caitlin, you know that I can't . . ."

"Fix this, Barry!" snarls Killer Frost but she can't tell how much of it is her and how much is Caitlin. "Do it now or I swear to God I will lose what little patience I have."

"This all started because I tried to alter the timeline and save someone I love. You want me to screw things up even worse?"

"I want him back!" Caitlin is shaking now but she can't tell if it's from anger or grief. "If it was Iris lying there in that coffin, you wouldn't think twice about doing it. So why is it you can save the person you love but the one I love has to stay dead? Who's the coldhearted one now?"

"I can't," admits Barry. "I can't make the same mistake again."

Killer Frost smirks because in her desperation she's found the right motivation. "Fine then, I guess you'll just have to take me in and be the big hero. Go ahead, walk me through CCPD so I can tell everyone there that The Flash hangs out in their forensics lab when he's not out saving the day. I can't wait to give the name 'Iris West' to all my new friends at Iron Heights. Do it, Barry, or I will make your life even more miserable than it already is."

"You wouldn't do that, Caitlin."

Her smirk is gone and there's fury in her eyes as her voice drops into a grim tone devoid of anything human. "You don't know what I'm capable of right now. Go on and run, Barry. Run!"

Barry braces himself and knows that he has no other choice. He knows he has to pay penance for his mistake but Caitlin and Cisco were innocent. They were just the victims of his ego. It's time to correct the course of all their lives. He runs past Caitlin or whatever is left of her shattered self. He runs as fast as he can because there are so many things chasing him. The ghosts of all his misdeeds are hot on his heels and he shifts gears to outrun them. He thinks about Cisco dying and feels the tears at the corners of his eyes. He's not going back to that moment though. He's going back to the root of the problem, that one tiny mistake he made. He prays to God, the Speed Force, and whatever else is listening that he can do this. He just wants one chance to make things right again.

Barry feels himself run so fast that he swears he's going to come apart. Time rewinds itself around him as he turns the clock back to one year ago. He sees the street that the Wests live on. He sees himself watch Iris go back in the house. He sees the look of pain and resolution on his own face as he made that decision. Barry watches his past self start running and he feels his legs explode with more energy than they have before. He moves so fast that he manages to tackle his past self before he can pick up enough speed.

"Great," says Barry from the past as he sees who's assaulting him. "Which Earth are you from?"

"This one," answers Barry. "Look, I know this sounds a little nuts even for our life but I'm you one year from now. I know that right now you're going to run back in time to save our mother. Don't do it. I know how much pain you're in but this won't help. This makes everything so much worse. You will lose Caitlin and Cisco in ways more horrible than you can imagine."

"So what am I supposed to do then?"

Barry takes a breath and decides to say what he wishes someone had told him a year ago. "Go back in the house. Go fall into Iris's arms and let her help you grieve. Hang onto the friends that you have and let go of the past. You have to or else you won't have a future."

The Barry of the past struggles for a moment because the temptation is so unrelenting. He finally nods though and Barry pulls him into a hug. He feels a sense of closure inside of him that he's never felt before. He wonders if this is what it's like to talk yourself down from the ledge. He wonders if this is what moving forward feels like. It feels good, better than he could have imagined. He watches his past self run back towards the West house and go inside. It feels right as he speeds back towards the present, the one that will be better than the disaster he created. He finishes his sprint through time and ends up at STAR Labs in the same moment that he left.

"Dude, watch it with the wind tunnel."

Barry smiles as he sees Cisco Ramon standing there adjusting his ponytail. He's scared for a moment that he's stuck in Flashpoint again but notices something else. Cisco's wearing a tuxedo for some odd reason.

"What's the occasion?" asks Barry.

"My brother's wedding," answers Cisco as if he's reminding Barry of something so completely obvious. "Barry, you look like you're going to a funeral or something. I know you're a speedster and you can get dressed in five seconds but you might wanna hurry."

"Your brother's wedding?"

"Yeah, Barry, the one where I'm the Best Man. Look, Caitlin and I need to leave if we're going to get there on time. You and Iris better be there, or else. You promised."

"I'm sure Iris will get him there, Cisco." Caitlin comes into the room and locks her arm around Cisco's, giving him a kiss on the cheek. "C'mon, we need to get going."

Barry notices that Caitlin looks very much like herself with a normal complexion and her usual hair color. Cisco also looks very normal and, more importantly, not dead. Barry doesn't think about it because he's too happy. He just crosses the room in a second and hugs both of them hard.

"Are you okay?" asks Cisco once Barry pulls away.

"Can't a guy just be happy at seeing his two best friends happy together?" asks Barry in return.

"You haven't been time-traveling again, have you?" questions Caitlin, a worried look on her face. "Barry, you promised you wouldn't try to change the timeline again after what happened with Zoom."

"I haven't," promises Barry and has never been so happy to lie to one of his best friends. "Trust me, Caitlin, everything's still exactly the way it should be. I promise it'll stay that way too."