This is the oneshot that sparked the Rylie v. Riley debate, and it somehow turned into an 11k word, very in-depth fic that was nearly impossible to finish as a oneshot. So now, I'm posting it here, on its own, in hopes that making it into a multi chapter fic will motivate me to finish before all I have written so far...
A mysterious illness goes around that puts a lot of people, including Mark and his friends, in the hospital. After being released, they each start to see and feel changes in their bodies. They grow different appendages and gain features of different animals. They even start to act like that specific animal. Can they...