I may have a decent idea that is both scary and rewarding. :twisted:
It could also be where you get your first weapon perhaps. You round a corner only to find a guy crouched on the side of the wall with his head down while also holding a pistol (or shotgun whatever you like). He notices you and with heavy breathing he says, "ah! ah! Can't you hear them? The voices.. they're everywhere! Getting louder.. Louder!"
He all of sudden drops his weapon, begins screaming down the hallway covering his head in a vain attempt to silence them and runs around the next corner. The screeming becomes all the louder perhaps followed by his voice saying, "No.. no im not ready!" you see a body being thrown back against the corner wall then a mysterious shadow dragging it back around the corner. You then see blood spatter against the corner wall. Then an aging person in a lab coat comes around that same corner with a sinister smile and in a somewhat soothing voice says, "Ah... so we have another patient..." and in the background you hear freakish laughs followed by a flash of light followed by.. nothing except the stain of blood on the corner wall and a weapon in your hands.
Not sure what you think but it could serve well to bring rewards and a nice dose of horror.