Caitlin's little sister Caiden comes to Central City for a visit at worst time possible. The Flash and Zoom are at battle. So Caitlin tries to convince Caiden to go back home but she stays in Central City. Something you need to know about Caiden is that she is suffering with stage 2 lung cancer, she has oxygen tanks to support her so she doesn't have to spend her life in a hospital. Caiden knows that Caitlin works with the Flash but Caiden doesn't know who he is. One day when Caitlin shows Caiden around STAR Labs, they run into Barry and Cisco and instantly Barry is developing a crush on Caiden. Since Caiden doesn't know who the Flash is, it puts her at risk cause Zoom knows who the Flash is and if he can't get to Barry, he'll do whatever it will take to get to the people he cares about. One night Zoom takes Caiden and Barry has to find a some way to get her back before it's too late.
4 parts