Never read the comics so this is solely based on the tv show. Personally I hope season 2 doesn't get rid of all the current actors, and supplements it with others seeing their younger bodies but them seeing each other as adults still.

A few points before the fic itself:

1.) Decided to go the route of 2002 since that would make the most sense for changing the timeline for the better, before Five time travelled and before Ben died. I expect the show will do this as well.

2.) Jeez, I can't believe I thought Albus Dumbledore was fiction's greatest monster, then I saw the show and met Reginald Hargreeves. He makes Dumbledore's abuse seem like loving behaviour.

3.) A fair few fics say "Klaus has PTSD" or "Five has PTSD" lets face it, all of the Academy have at the very least serious neglect and abandonment issues, and most of them if not all have PTSD or probably will do in season 2. I'll be trying to cover this in the story, but as I have no personal experience of PTSD or abuse, I must apologise in advance if I misrepresent people with it and must beg forgiveness for any unintentional offense.

There was such noise and chaos. The theatre whirled with the glowing light coming from Vanya as she played her violin in a daze, the roar of gunshots and the bow strumming across the strings drowning out everything else, everything except the frantic calls of the Umbrella Academy to one another as they tried to fight through the destruction to stop the end of the world. Then everything came crashing down around them. Ben, and god how they had missed Ben, was amongst them, killing their assailants with apparent ease as Klaus channeled him, surprising all of them with this ability, Vanya holding off all of them at once with apparent ease, Allison firing the gun and Vanya collapsing, and then of all things, the Moon hurtling towards them, a catalysmic fireball destined to eradicate humanity.

'If this is it, it's not so bad.' Five thought to himself as he saw the rocks speeding toward him. 'Well everything was for nothing but I guess if I had to fail, at least these idiots are with me. I get to die with my family. What a depressing final thought that is.'

"So much for saving the world." Klaus said.

"If only Sir Reginald could see us right now, huh? The Umbrella Academy. A total failure." Diego said.

"At least we're together in the end. As a family." Luthor said as a brainwave hit Five.

"This doesn't have to be the end." Five insisted.

"What are you saying, Five?" Luthor asked.

"I think I have a way out of here, but you have to trust me on this."

"Nah I don't think so." Luthor, Diego and Klaus said as one.

"Well then we might as well accept our fate because in less than a minute we're all going to be vaporized." Five told them.

"What's your idea then?" Diego asked.

"We use my ability to time travel." Five explained. "This time, I'll take you with me."

"You can do that?" Diego asked.

"I don't know, I've never tried it before." Five said.

"What's the worst that can happen?" Diego asked the others.

"You're looking at it. A 58 year old man inside a child's body, so there's that." Five replied with the others looking between everyone else.

Everyone else gave agreement that it couldn't be worse as well.

"Okay, great, Luther, grab Vanya."

"Wait, should we be taking her with us? If she's the cause of the apocalypse, isn't that like taking the bomb with us?"

"The apocalypse will always happen, and Vanya will always be the cause unless we take her with us and fix her." Five explained.

'What part of this doesn't Luthor already grasp?' Five fleetingly thought to himself.

Five scrunched his face in concentration as the others looked around at each other, all praying desperately that it'd work, that they'd be anywhere other than where they were at that moment. Electricity began to crackle as the temporal barrier opened up for Five and in a blink, they were gone and the Earth with them.

2002

A bright flash of light lit up the Icarus Theatre as a group of kids appeared out of nowhere, landing on the stage in a mess. Groaning, the kids began to untangle themselves, giving each other a glance as they did so before freezing.

"We...did it." Five muttered, in a daze as he saw everyone in their younger bodies. Looking up at the fully intact lunar body of the Moon, seeing that there weren't flames consuming everything.

"We're in the past?" Diego asked as he took in his surroundings. All was quiet, it seemed it wasn't a performance night. Luther and Allison looked at each in worry, Klaus was holding onto Ben for dear life, and Vanya was lying on the floor, peaceful in her slumber.

"It worked!" Klaus said as he hugged Ben, drawing everyone's attention to the pair, eyes widening as they realised Ben as back amongst them.

"I wasn't sure it'd work, but I had to try." Ben admitted as he was engulfed in hugs from the others, never wanting to let him go again.

"I was pretty confident it'd be fine. We were transporting our consciences, so as long as you were within the circle, I assume you were holding onto Klaus? You'd be with us." Five explained as Ben nodded.

Clearing his throat, Luther got the attention of the others.

"What do we do now? We've got to get out of here."

"We need to go to the Academy. We can't alter things too much, the Commission will be after us already." Five told the others. "If we don't alter too much at once, it'll be harder for them to track us to here and now, and we can work on sorting out this mess once and for all."

"What do we do about Vanya?" Klaus asked, lookig down at their comatose sister.

"We get her into her bed. I'm sure she'll be fine in the morning. When she wakes, maybe let me explain it to her, or get Allison to help keep her calm."

"Shouldn't we put her back in the cell in case she does freak out?" Luthor asked.

"Are you intentionally being an idiot?" Diego said before Five could cut in. "That's part of the reason she destroyed the Academy, because you locked her in there and we didn't stop you. Put her back in and she'll certainly go unbalanced again."

Five couldn't help but nod at this. Maybe not the exact wording he'd have used, but it was the same point he'd have tried to convey to Luthor. Repeating their father's mistakes was a recipe for bringing the Apocalypse again, this time only seventeen years earlier.

"What do we do then? How do we help her?" Allison asked.

"We take her home, when she wakes, we give her a pill to stop her hurting herself or anyone else if she takes it badly and we explain it to her. We help her to control her powers, we finally live like an actual family and if dear old dad tries to hurt any of us, we leave, not before I teleport him to a roof and throw him off." Five explains.

"You'd have to stop me from using The Horror to rip him apart." Ben frowns as the rest look at each other, and begin to laugh. What else could you do in a situation as messed up as this one?

/

A flash of light lit up a deserted field as two figures appeared, one of them clutching a large black briefcase in his hands.

"Where are we, Hazel?" Agnes asked as she looked around at where they were.

"2002." Hazel told her. "Here we can have a fresh start. Years until the Apocalypse, hopefully we can find a way to prevent it as well."

"How would you do that?" Agnes asked him.

"I'll think of a way, don't worry." Hazel assured her. "For now, let's look at setting up your own donut shop in the country." He smiled as Agnes nodded at him.

Hazel already had a plan, of course. He and Cha-Cha were to protect Vanya Hargreeves to ensure the Apocalypse occurred. How best to stop it? Stop Vanya Hargreeves.

/

"Let's get her onto the bed." Ben said as Luthor gently placed Vanya in her bed and stepped back, the rest of the Academy looking at each other.

"What do we do?" Diego asked.

"Act normal." Five told them. "Go about business as we would. Train, fight crime and work to make sure the end of the world never comes about, at least whilst we have a chance of stopping it."

"Sounds simple enough." Klaus snorted.

"We'll figure it out." Allison assured him. "It'll take time, but we're here now, and as a family this time."

"First, we need to find Vanya's medicine." Five told them, directing the others to look around the room for her pills, Diego finding them a few moments later.

"Lift her head up." He told Allison, who lifted Vanya's head up and Five opened her mouth and slippped the pill inside her, Klaus moving over to them.

"Well since I have the most experience with taking pills and everything." He said, massaging Vanya's throat to make sure she swallowed her pill, when that was done, Allison lowered her head back onto her pillow.

"That sorts it then. Let's get to bed, before dad realises something is up." Luthor said, heading out of the room in a hurry. The rest of the kids followed him, most of them looking at each other and at Vanya with a worried look.

As Ben closed the door behind him with a sad smile, a quiet gasp came from the bed.

As Vanya opened her eyes.