Drabble. 100 words exactly. I own nothing but a DVD copy of Dr. Horrible's which I watch repeatedly. Spoilers for Act III.
He never cried.
Not at the funeral, where he sat in a back row as hundreds of people mourned over the girl he loved. They hadn't even known her.
He didn't cry when he burned the pictures he had taken of her.
He couldn't cry.
He hid all his emotions behind the mask of Dr. Horrible, locking them away into a little box, like a failed experiment. Every day, that experiment faded a little more into the dark, and Dr. Horrible became a little bit more of who he was.
And every day, Billy got a little closer to Penny.