Doc: "All right, we'll get the DeLorean and get ourselves back to the future."
Marty: "Oh, listen, Doc, I tore a hole in the gas tank when I was landing so we're going to have to patch it up and get some gas."
Doc: "You mean, we're out of gas?"
Marty: "Yeah. It's no big deal. We've got Mr. Fusion, right?"
Doc: "Mr. Fusion powers the time circuits and the flux capacitor, but the internal combustion engine runs on ordinary gasoline. It always has. There's not gonna be a gas station around here until sometime in the next century. Without gasoline, we can't get the DeLorean up to 88 miles per hour."
Marty: "So, what do we do?"