The Flash - Season 5 -

: She discovers that Killer Frost did not originate from the particle accelerator but was a result of experiments performed by her father, Thomas Snow.

: Struggling with the burden of his powers, Cisco eventually chooses to take a meta-human cure to live a normal life. The Flash - Season 5

The Flash Season 5 Episode 8 Review: What's Past is Prologue : She discovers that Killer Frost did not