Bending over to pick up the smashed test tube, he winces as he pricks his thumb. "Dammit!" he curses. He should have been wearing gloves in the first place, but it had been a long night. He sucked his finger lightly, curious that the pain quickly was replaced by a tingling sensation.

He looked down at the cut finger to see it healing visably, but that didn't worry him nearly as much as the skin around it turning rougher, a thick callous building up even as hair sprouted from the skin around it. Soft and fuzzy at first, it soon sped up and was advancing down the finger and spreading to the rest of his hand.

Story idea suggested by  skgyae for  RojAdrik . Enjoy!