Part 1- A Crisis is Imminent

Earth-2- Central City

Jesse Quick sped into the cortex of STAR Labs, having just dropped off Evan McCulloch, AKA Mirror Master, at Iron Heights.

'Nice one, Jesse,' said her father, Harry.

'Thanks,' answered Jesse. 'But he won't talk. We have no idea what he or his rogues are planning.'

'Jess, this is still a win,' argued Harry. 'We will-'

Before he could finish, all the alarms started going off with a furious intensity, as STAR Labs was rocked by an earthquake.

'What was that?' asked Jesse.

'I don't know,' answered Harry. 'You're going to be needed out there.'

Jesse nodded, speeding away to find out what was happening.

Jesse came to a stop outside the CCPD, looking up at the sky in shock as it turned blood red. She activated her comm device.

'Dad, the sky has turned red. What's going on?' Jesse asked, receiving nothing but static in response. 'Dad?'

'Jesse…Can…Me?' Harry's voice broke through the static, rapidly fading in and out. 'It's…Anti-mat-'

'Dad, come in!' Jesse cried, panicking. She turned round and looked back at STAR Labs. As she did so, the red sky was consumed by a wave of white energy, destroying everything it touched. Tears streamed down Jesse's face as she watched it destroy STAR Labs.

'DAD!' Jesse screamed, as the wave sped towards her. Jesse turned and ran, as fast she could. Whatever this energy wave was, it was destroying the whole planet. Jesse looked back over her shoulder, noticing the wave was catching up with her, even at full speed. She opened a portal to the Speed Force, intent on going to Earth-1, to ask Team Flash for help. As she entered the portal, the energy wave hit her, and she screamed in pain, losing control of her trajectory.

As she fell uncontrollably through the Speed Force, she saw that what was happening to her Earth was happening to all of them. The Multiverse, being destroyed by one singular Crisis. She saw her friends and many other heroes trying to fight it. She saw and heard it all.

'Calm down, Electric Guy. The name is Black Lightning. / Oliver, it's time. Has the planet been evacuated yet? / Consider us even, John Constantine. Heh, heh. Constanteen. Is it? I don't care. / Oracle, it's Huntress. Come in. / Novu said the Flash must die in Crisis. He never said which one. / HOLY CRIMSON SKIES OF DEATH!'

Jesse could scarcely believe the horror of what she was seeing. She saw another portal opening up beneath her, as she fell through it.

The TARDIS- hurtling through time and space

The Doctor danced around the console unit, rapidly pulling levers and pressing buttons, as her three companions- Ryan, Yaz and Graham- watched her intently.

'Doc, I don't mean to complain or anything, but when exactly are we going to get to this space restaurant? Cos I'm really hungry,' Graham asked.

'Calm down, Graham. The wait will be worth it,' answered the Doctor. 'The Terrapika Fripec is the best restaurant in the entire universe. The food is genetically engineered so it tastes better the hungrier you are.' With that, the Doctor looked up at the computer monitor and frowned.

'Wait, that's not right,' she said, pointing at an anomaly. 'What's that?' Suddenly, a blue portal opened up, spitting out jolts of multi-coloured lightning all over the control room, as a streak of yellow lightning shot out of the portal, crashing into the side of the console, revealing a woman with long brown hair with a black mask, wearing a red suit with yellow trousers, with a winged lightning bolt emblem on her chest. The Doctor ran to her side, scanning her with her screwdriver, as the portal closed.

'Are you ok?' The Doctor asked. The woman seemed to be unconscious, so the Doctor sat her up against the console. The woman suddenly woke up and grabbed onto the Doctor's lapels, startling Graham, Yaz and Ryan.

'Have- have to get to… Earth-1,' the woman stammered, short of breath. 'Warn them…A Crisis is Imminent…' The life seemed to be slipping from her body. 'Tell Wally I lo…' The woman stopped talking, as her body faded away, into nothing.

'What just happened?' asked Ryan, after a few moment of silence.

'Her entire cellular structure just… collapsed,' said the Doctor, standing up and checking the readout on her screwdriver.

'What could do that?' asked Graham, all thoughts of food gone.

'Anti-matter,' the Doctor stated gravely.

'Anti-matter?' asked Yaz. 'Like the stuff that powered the Tsuranga ship?'

'Not exactly,' answered the Doctor. 'That was safe and refined, solely generated to provide energy. This anti-matter is raw, destructive power, capable of annihilating all matter in…' The Doctor trailed off at this point.

'In what?' Ryan asked.

'In an entire universe,' replied the Doctor, operating the TARDIS controls, before looking up at the screen. 'I'm scanning for a universe that exists on that woman's specific dimensional frequency. And of course there isn't one.'

'What are you talking about, Doc?' said Graham. 'Are you saying that she came from a whole other universe?'

'She did,' confirmed the Doctor. 'But it's all gone. Every piece. Vaporised.'

'So how did she get here?' Yaz asked.

'That lightning. I never thought it was real, just a myth,' the Doctor began. 'The Speed Force. A conscious universe that can manipulate space-time. If someone becomes connected to it, they can run impossibly fast, fast enough to travel through time and space, even to run to whole other universes. The anti-matter must have knocked her off course as she entered the Speed Force. She mentioned trying to get to Earth-1. Presumably, an Earth parallel to her own, where she had friends that she was trying to warn about the imminent Crisis.' A look of grave realisation came over the Doctor's face. 'Oh, no…'

'What is it?' asked Ryan, getting worried now.

'Worlds will live, Worlds will die, When the Crisis is imminent, The Harbinger must fly. To find heroes, And have a chance that is even, To save the Multiverse, Unite the Seven,' the Doctor muttered.

'What's that?' Yaz asked.

'It's an old nursery rhyme from my home planet,' explained the Doctor. 'Based on an even older prophecy that was declared forbidden knowledge. It speaks of a Crisis, one that would destroy all universes in existence. The whole Multiverse.'

'Right, I get it,' said Graham. 'That girl was the Harbinger, and you're one of the seven heroes that she needs to find.'

'No, she doesn't fit the description from the prophecy,' the Doctor replied. 'I think she was just a victim. But if the prophecy is coming true… I need to check the Multiverse.' The Doctor started operating the controls. 'Opening up the dimension scanners.' The screen lit up with hundreds- maybe thousands- of little dots.

'What are those?' asked Ryan.

'Each dot is a digital representation of all the universes around us. That's us,' the Doctor said, pointing. 'Then there's Pete's World, the Celestial Toyroom, the Solitract, E-Space. Dimensional signatures strong. That won't last long.'

'Wait, some of those dots are disappearing,' noticed Yaz. 'What's happening?'

'Huge waves of anti-matter, destroying whole universes,' said the Doctor. 'What could do that? Who could do that? Omega? No, this is too big, even for him.'

'Hang on,' Graham piped up. 'What's keeping us safe?'

'Absolutely nothing,' the Doctor replied. 'One big surge, and our entire universe would be destroyed. Even the TARDIS couldn't survive that. I need to know what's happening. I need to get out there.' The Doctor ran back to the console, and lifted up a panel in the floor, throwing random pieces of tech over her shoulder. 'Where is it? Aha!' The Doctor pulled out a round, silver device with a large yellow button on it.

'What's that?' asked Yaz.

'A dimension cannon,' replied the Doctor. 'Thank you, Jake Simmonds! I can use this to breach into other universes, investigate whatever this Crisis is.' The Doctor opened up a panel on the back, and took out a computer chip. 'Not a particularly safe method of jumping universes, but with all this anti-matter softening up reality, shouldn't be too dangerous to push through the dimensional boundaries.' The Doctor pulled out another device out of the floor, and plugged the chip into it.

'Wait, is that Krasko's vortex manipulator?' asked Ryan.

'Yep,' the Doctor said. 'I repaired it, just in case we ever needed it. Now seems as good as time as any.' The Doctor strapped the device onto her wrist.

'So, what do we do?' asked Yaz. 'Do we hold on to the device?'

'Nope,' answered the Doctor. 'We don't do anything. I do.'

'What?' Graham exclaimed. 'You're not doing this without us, Doc.'

'I have to. This device will only carry one person,' said the Doctor.

'How long will you be gone?' asked Ryan.

'Time doesn't move between dimensions, so I can be gone for years, and pop back a second later,' explained the Doctor, sonicking the device, followed by the TARDIS console. 'I've synced the device to the TARDIS. It'll track me across the Multiverse. If anything happens to me, the TARDIS will take you home.'

'Good luck,' said Graham, Yaz and Ryan in unison. 'Come back safe,' Graham finished.

The Doctor nodded, tapping at the device. She took one last look at her friends, as the device opened a breach, swallowing her and snapping shut.

'So what do we do now?' Ryan asked.

'Well, it might not be the Terrapika Fripec, but I've seen a canteen down the corridor,' said Graham, causing Yaz and Ryan to look at him. 'What? I'm still hungry.'