Cisco: Joe was right. You were there, that night, 15 years ago in Barry's house. You killed Nora Allen.
Harrison: It was never my intention to kill Nora. I was there to kill Barry.
Cisco: Why?! You're his friend. You've been teaching him how to...
Harrison: Go faster, I know. It's a means to an and and I'll tell you why. Because I have been stuck here, marooned here, in this place for 15 long years. The Flash and The Flash's speed, is the key to returning to my world and to my time and no one is going to prevent that from happening.
Cisco: I can help you.
Harrison: You're smart Cisco, but you're not that smart.