Story scraps: Insanity

Insanity

Fat drops of rain thudded against the window, sliding down like tears against the glass. He worked feverishly in the near darkness, nimble and talented hands tightening bolts, screws, putting on parts, and more. A flash of lightening filled the window, illuminating his hunched figure and horribly bloodshot eyes.
"I'll show them," he muttered. "I'll show them all. I'll show them that I'm not insane…" He let out a laugh that sounded more like a cough and finished tightened a screw.
Thunder boomed and a flash of lightening followed shortly thereafter.
"Bret Thompson, you'd better not be messing around with my lab equipment!"
"Leave me alone, mom!" the man known as Bret yelled back, face twisted into irritation.
"I don't like you spending all that time in the basement!" his mother yelled back. "You've been in there for days, hardly even coming up for nourishment!"
Hissing, the man continued to work.
"This will be my greatest invention yet. And I'm almost done, yes, I'm almost done…"
And so Bret worked, through the night, and through the day ahead until it was night again.
"Yes," he murmured hoarsely, thunder booming and lightening flashing. It illuminated his pale, sickly face and arms and even more bloodshot eyes. But there was something else in his eyes.
"Finally!" he cried triumphantly, painfully straightening to observe the results of his tireless building and tinkering. Not only his hands and arms, but his legs, too, shook from exhaustion.
"I… have… finished!" Bret cackled wildly, a cackle of a true madman. He was a madman that lived in his mother's basement, but a madman, nonetheless.
Yes, besides being horribly red, there was something else in his eyes: insanity.