"Not everything does. Some things in the future run on very small amounts of lightning."

Because she doesn't know how electricity works well enough to explain it to a pirate. Darcy turns the keys in the ignition and then locks the car.

"Undine told me you stopped by. You want to explain why for me?"

To get his side mostly. Undine told her very little about the shape of the actual conversation, and... there is a very small hope that she just misinterpreted his mannerisms and it wasn't a 'what are your intentions with Darcy' situation.