(Well that should have been expected. Eddie just sighs patiently and steps closer to Laura, grabbing her hand and pulling it up. He pulls open her pinkie before hooking his around it.)

This is called a pinky promise. It's probably one of the most secure way to make a promise. When you make a pinky promise, you can't go back on the promise no matter what.

(But that was just one of the most established forms of a promise. The other way was a way that, if he thought to mention it, would not result in a pleasant outcome for Eddie. That promise was a promise that was currently keeping his mind locked up.)