The Flash, Season 4

Iris:
Where you gonna go?

Killer Frost:
I know a guy who can breach me to another Earth. Start over. Escape Amunet. Be who I want to be.

Iris:
And that's Killer Frost. Right?

Killer Frost:
Don't be cute, West. You can't stop me.

Iris:
I wasn't planning on it. Look. I know you could kill me. Just like you could have killed Amunet tonight, or Cisco six months ago. But you didn't. There is a part of you that is good and decent. You just don't know how to accept it.

Killer Frost:
You think you know me now?

Iris:
No. But I do know what Caitlin looks like when she's scared. And you have that same look in your eyes right now. [puts her hands on Killer Frost's shoulders] You're just as afraid of being Caitlin as Caitlin is of being Killer Frost.

[Killer Frost's face goes from scared back to tough.]

Killer Frost:
If you still want to have a hand for Barry to put a ring on,... I suggest you move it. [Iris complies and Killer Frost leaves.]