TMA spoilers for all five seasons!
TMA Ringworm(?) AU where prior to Prentiss’ corruption, Nikola kidnaps her to use her skin or smth bc she thinks Jane is very pretty which is often an advantage when wearing someone else’s face. As a result, Prentiss is far away from the wasps nest and Nicola takes such good care of her skin that after a while (perhaps a few months?? A habit like that would be hard to break), she stops picking at it, preventing her from becoming an avatar of The Corruption. We know Prentiss was sort of afraid of the wasps nest, so after “saving” her from it, she develops a kind of trauma bond/Stockholm syndrome feeling towards Nikola and decides to stay with the circus, especially if it means staying away from the wasps nest. This could lead to Prentiss becoming an avatar of The Stranger inadvertently which would cause all other kinds of issues, no longer having the worm attack in season one, this leads to:
Tim and Jon not being incredibly scarred (both mentally and physically)
jon and Martin not bonding in the closet (pun intended)
Tim not becoming depressed in Season 3 as Sasha wasn’t taken by the NotThem
Jon not being marked by the corruption, and therefore delaying the apocalypse
Jon probably not finding Gertrude’s body as soon as his did, meaning none of that season two paranoia we all know and love