No Way You... I Though You Were Dead

snowbarry fanfic. centers mostly in their relationship in the 3 years that they've known each other, until the come across someone that will flip their worlds upsidedown, specially Barry and Caitlin's.
Their ages are:
Caitlin = 21
Barry = 21
Cisco = 22
Iris = 24
Eddie = 23

can you guess of who am i talking about? if you can tell me in the comments.