There they are!

You dart down corridor after corridor, each office whizzing past in a blur. The speed is incredible and you feel exhilarated by your new power. You come to a screeching halt to re-acquire the scent, then take off once again. The smell of Sarah is much stronger now, and it is beginning to mix with that of Keira, a lovely blonde you would be happy to fang and fuck. Or let Sarah have once you had given her the gift. You are closing in now, you can even hear the frantic patter of their feet as they run for the exit. You slide across the floor, coming to a halt perfectly at the turning of the final corridor. And there they are, mere metres from the fire exit!
"No!" You shout, and Keira glances around with scared eyes, but Sarah keeps running. You launch yourself forward, but Sarah has already got the door open. You are too fast! There is no way they'll both get through in time. You charge head first... and slam painfully into the metal door. You slide back on the floor, confused and infuriated. You look up to see Keira smashing the door lock console. Clearly the girl shut the door at the last second, preventing you from reaching Sarah, but trapping herself in the process. You leap up and smash both fists into the door, glaring angrily at Sarah who stands outside of the door, screaming soundlessly at the glass. She recoils, horror and fear on her face, but the door doesn't give. You can most certainly bash it down, but by the time you do she will be long gone. You roar as Sarah begins to back away.
"Run Sarah!" Keira shouts, her eyes flooding with tears. You glare at her, then cast around back at Sarah. You know she can't hear you so you settle for a smoldering stare instead. Finally, Sarah dissolves into the night, leaving you breathing deeply and staring into space. Slowly, you become aware of a sobbing sound at your knees. You turn to see Keira, the bitch who kept you from the one you wanted most. She has shoulder length, shaggy blonde hair, and pretty features. Her slim body is clothed with a simple pleated skirt and a frumpy sweater several sizes too large for her. Despite her petite form and pretty looks, you know that Keira is older than you, and her face shows it slightly, the deeper laugh lines juxtaposing nicely with her round cheeks. You decide she needs some attention.