You need to get to the bottom of this so when the teacher steps out into the fire escape to smoke you sidle up to Mary at her lab bench. As usual, she gives no sign that she notices you aside from a little involuntary cringing.
"Uh Mary," you mumble. She still doesn't react. You clear your throat.
"OH MY GOD WHAT," she screams at you, little bits of worm guts flying off the end of her scalpel.