A/N: Last July I began posting a countdown to the premiere of Supergirl, lasting 100 days and updating daily, until the premiere of the second season. Since then, I caught up to and got into the rest of the Arrowverse, so this year's countdown will feature each of Supergirl, The Flash, Arrow, and Legends of Tomorrow. Now as I can only crossover two shows at one time on here, there will be two volumes of this singular project: 100 Days of Arrowverse 2017: Supergirl & Arrow, and 100 Days of Arrowverse 2017: The Flash & Legends of Tomorrow. I'll be alternating from one to the other depending on what's next, but there will be a new chapter every day in one or the other. This is break down, in sequence:

Days 1-20: 5-part stories for a single character (Lena Luthor, Jesse Wells, Thea Queen, Sara Lance)
Days 21-40: 5-part stories for a pair of characters (Alex & Winn, Cisco & Caitlin, Quentin & Daughters, Mick & Amaya)
Days 41-80: 10-part stories for each show (Team Supergirl, Team Flash, Team Arrow, Team Legends)
Days 81-100: 20-part crossover (I haven't figured out how I'll split that one over the two volumes yet.)

100 Days of Arrowverse 2017 Volume A: Supergirl & Arrow

95 days until Supergirl - 96 days until Flash & Legends - 98 days until Arrow

(The Flash: Jesse Wells, part 1 of 5)

Waking up on Earth 3 wasn't any different than on either Earths 1 or 2, up until she would open her eyes and see the world past the window. When she had first crossed on to this Earth, to carry on looking after the city in place of the Flash they had lost to the speed force prison, all she'd had to go on was that choice. But soon she had to begin looking to what her life would be like here. It had started with an innocent lie, taking up residence in Jay's home, claiming herself as a visiting niece, looking after that home while he was out of town. Surely Jay would understand. She had slept on his couch ever since. Making money, keeping herself stocked on the food her being a speedster would require, she could handle it, too.

She also knew she couldn't go at this alone. She knew very little about this Earth, what set it apart from the others, and what kind of foes she might come across beyond the garden variety criminals. Her first ally presented herself when a glance at a television screen had presented her with a familiar face… Iris West, reporting from the Mayor's office…

Jesse had sought out this Earth's Iris West, who all in all felt well in line with the two she had encountered before. She hadn't revealed herself, her abilities, just yet, instead making some inquiries. Her pointed line of questioning had led to the reporter putting her in touch with a local private investigator, who specialized in 'those cases.'

Her name was Patty Spivot, and Iris had been right. Jesse had learned a lot from her, too. She had heard the name before, on Earth 1, though she couldn't say she knew more than how she had been with the CCPD before heading off to become a CSI. And here on Earth 3, this connection to science had put her in touch with yet one more ally, once the detective had gone and pieced together that she was a speedster. She had personally introduced her – as far as she knew – to Caitlin Snow.

As disparate as the two versions she'd met before, this one had been something else entirely. She was… frenzied? The words 'mad scientist' came to mind at once. But having her around, like the others, had been indispensable.

Because it had been the four of them since then, and before she knew it, she was doing exactly what she'd set out to do in coming here. Earth 3 had a Flash back to look after the city. Once they had learned of the presence of this new speedster, it seemed many of those in Central City wanted to challenge her and see if they could beat her. Iris and her reports were spreading the word: they could not. It didn't mean they stopped trying.

And now that day saw a new challenger rise to call her to the arena. The most notorious gold thief known to the area, in and around Central City. Lisa Snart was calling her out… and she would answer. Her team was ready, too.

But at heart, this was her undertaking. She had not set out for this life, back on her Earth. It seemed her whole life had changed in the last couple of years, but none of it felt beyond her. With her suit on, hard-earned in proving herself to everyone else, feeling the speed coursing through her, waiting to be unleashed, she couldn't be any readier. She would find this thief and put her where she belonged; this part was easy. It was the rest, the things she would sweep away, rather than stop and consider them. She would get nothing good in going down that route.

Her challenger aided in her distraction that day. Lisa Snart had evaded her this time. Round one to the gold thief. Round two would be for another day. Until then, her biggest concern, beyond any other issues for her to resolve around the city, would be Iris, again, seeking to introduce her to her brother; not here, not that one.

See you tomorrow in Volume A for Arrow!