Number Two/Funny

"'67 Doc: I took some LSD and it just came to me. (Marty's mouth falls open. He looks over at '85 Doc in the window who simply shrugs)"
 * When Marty asks how '67 Doc came up with his plan of getting 1.21 gigawatts into the DeLorean this time (which involves a time bomb and power lines), this happens: