A few seconds later, the chanting comes to fruition.  A watermelon-sized fireball arcs from one robed student's hand towards the professor's back, and a vague shimmer washes over the room -- not unlike a heat distortion, but it looks to Lori like a Communication/Empathy spell of some sort.  A poorly-controlled mana outflow, she knows well, can often result in a visual effect.<br/><br/>"<em>Zilgrak!</em>"  Professor Willard whirls, gesturing with one hand and neatly catching the fireball out of the air with the other.  "Thank you for proving my point," he says sharply, turning the projector on.  The screen reveals instructions Lori recognizes, for a Sense Foes spell.  "A mundane," he continues, still holding the fireball, "would have had to rely on old-fashioned, unreliable measures like reading your body language to know whether he was likely to be attacked.  I, on the other hand, was able to determine whether someone was hostile toward me with the simplest of spells."  He smiles, and it isn't a very nice smile at all.  "See?  It's better this way, and that's why you're here."