Yeah, mother nature doesn't like it if you rearrange the furniture.
Jones: How'd you meet him?
Cassie: I told you. They found a recording that I make and the future you sent him here to find me.
Jones: And you believed his story?
Cassie: No, he brought my watch with him from the future and he broke time.
Jones: The same watch from his time?
Jones: That's profoundly risky.
Cassie: I know, it caused a paradox. It almost killed us.
Jones: Yeah, mother nature doesn't like it if you rearrange the furniture.
Jones: That must have been extraordinary to see; matter coming in contact with itself.