The first chapter of "Bionics", the story about what happened between Zachary getting shot and the S5 team being formed is up on the AO3 .
It's currently roughly 10 chapters, but especially in the second half are still gaps that will have to be filled, so final length may be longer. Anyways, hope you'll have fun with it.
Summary: In the first TV-ep, Zachary is shot, Eliza is captured, and at the end of the episode, we see him with the team and weapon-grade bionics.
Well, this story is my take on what happened between those two moments. It covers Zach's implantation and struggles to deal with it, Niko and Goose getting their implants, Doc learning about them (and the commander), Goose getting ALMA, and the S5's being formed...
https://archiveofourown.org/works/89238176