Try to sneak up and save Keira.

Something is wrong, very wrong, and you aren't about to leave Keira behind. You leave the security office, removing your impractical heels, and try to make your way along the corridor as quietly as possible. As you approach the records corridor you hear quiet voices, but can't make out what they are saying. You see Keira, and as slowly and gently as possible you approach.
"Keira!" You explain in a low whisper. "C'mon we have to get out of here!" Keira looks up, surprise and relief apparent on her face, but at the same time you here from Beth from the corridor:
"Hey... Theresa! I did smell someone!" You grab Keira's hand and sprint away, sliding on the floor in your socks.
"Oh nononono." Keira sobs behind you, but you ignore her.
"Is that Sarah and Keira?" You hear Beth call out behind you, her voice worryingly close. "Where are you going? We only want to have fun." You glance back to see Beth easily running after you, her bare feet and slender, muscular legs propelling her forward at an alarming rate. You hear a muffled crash from an office to your right, but keep up the pace.
"Don't worry Keira, we can outrun that skinny bitch any day of the we-" You are cutoff by the sound of a huge crash infront of you as Theresa smashes through the wall. Her ebony skin is caked in plaster, and you can see that she is all but naked.
"Found you." She says calmly, baring her perfect white fangs. You turn and see Beth trotting up behind you a grin and a musical laugh on her lips.
"What are we gonna do with them 'Resa?" She says with a giggle. The two women start to close in on you.
"Hmm." Theresa muses, her arms crossed under her voluminous, firm, breasts. "I think we should take them one at a time. Let Sarah see the change and then make Keira taste her?" Keira grips your hand and whimpers, you squeeze back, but you know this is the end of the line.
Beth laughs again: "That's a great idea 'Resa! Hmm... you let me have Keira and you can have Bob all to yourself later?"
"You know me so well already Beth..." Theresa croons, then darts forward in perfect unison with her partner. Keira screams as she is ripped from your grasp. You try to grab her back, do anything, but Theresa already has you, she pulls you around, pinning your arms behind your back. You kick at her feet, but to no effect. She leans in close, her lips brushing your ear.
"Watch." She whispers, you are helpless to resist. You stop struggling and look up to see Beth and Keira. Keira is crying and Beth is holding her from behind, one arm under her breasts, the other stroking her hair. The vampire, you have nothing else to call them, is nibbling at her ear, her long tongue questing around Keira's cheek. Keira 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. Beth's hair is in stark contrast, falling in a curly red haze around her head. Her piercing blue eyes, which seem to glow, are examining Keira intensely. She slips her holding arm under Keira's sweater with a giggle, and Keira sobs hard. You see Beth's hand questing around, feeling Keira's flat busom. Then her other hand slips under the waistband of your friend's skirt. You grit your teeth but can't help but imagine the taloned fingers carressing Keira's clit. The two hold this position while Beth places a line of kisses on her captive lover's neck, until she rests at the base. There she pauses, and Keira's sobbing stops, replaced with wide eyed terror for what is to come. Then, a smile turning the corner of her red lips, Beth bares her fangs and bites down. There is a small squirt of blood and Keira screams instantly going slightly limp. Then you can't help but watch Beth as she gulps at your friends neck, her eyes closing over in pleasure. You feel Theresa quiver behind you, and one hand creeps around to caress your crotch gently. Shortly, Beth pulls away, the wound completely clean and devoid of blood. You see a small drip on the corner of the vampire's mouth, but her long tongue quickly wipes it away. You watch in horror as your lost friend transforms. Keira's dull blonde hair adopts a hazy golden sheen, the shaggy cut morphing into a perfectly formed crop. Her cheekbones sharpen slightly as the fat drains from her face. Its hard to tell beneath her baggy sweater, but are sure you see her breasts grow and perk up. Her limp hands grow cruel talons, and finally she opens her eyes which glow a deep gold. She smiles, her lips splitting to reveal razor sharp fangs. She turns, finding Beth's lips for a passionate kiss, then she fixes you with a stare.
"It's bliss Sarah." She says simply, straightening up and strutting towards you. "Pure bliss." She reaches for the hem of her sweater and pulls it off. Then, her hips and skirt swaying seductively, she unbuttons her shirt to reveal her perfect bra less chest. Her nipples are a light pink against her incredibly pale skin. She arrives, and Theresa releases your arm. The fight has left you. You stare up into your friends eyes as she plants a kiss on your quivering lips. A tear rolls down your cheek. Keira looks suddenly sad.
"There there." She says, wiping it away with one smooth thumb. "No need for that." She leans in close, kissing your neck gingerly. "Only happiness now. Now and forever." She pushes her fangs into your neck. The pain is immense but you are unable to scream. Keira grips your buttocks, pulling your crotch into hers, your breasts pressing together in a dark parody of a lovers embrace. You grow cold and the light gives way to dark, the only thing you are aware of is a tingling at the core of your being, and Keira, pressed tightly against you. After what seems like an eternity, your eyes flutter open, and you look directly into the golden eyes of your saviour. Theresa and Beth have moved on, but Keira is holding you. She smiles, and you smile back, your mouths and tongues meeting in a tender kiss. When Keira moves away, you push forward, your hands reaching for her breasts. You feel the points of your talons scratching her smooth skin pleasingly. She responds in kind, fondling you vigorously. You reach under her skirt, twining the vampire's panties around your index, then you snap them free, eliciting a short laugh from your lover.
"Naughty, naughty." She says. She undoes your trousers. You admire her swaying breasts as you watch her work on your underwear, sliding them and your trousers free. You bring your slender, clean shaven legs up in a flourish as your clothes pop free from your ankles, and then entwine them with her so that her skirt drapes over your embracing pussies. She looks pleased at this complicated maneuver, and you smile as you begin to push your clit into hers. She groans and pushes back, and soon you are moaning in ecstasy too. The position is complex, but your flexible new forms execute it with ease. Soon you are grinding furiously, your bodies in a complex tangle of roaming limbs. You both reach climax together, Keira unhooking her legs from beneath you so she can wrap you with them. You feel her quivering pussy against your abdomen as you both orgasm furiously. Her undulating breasts brush yours. Eventually you collapse together, your lips locked, entirely satisfied. Satisfied, that is, sexually. Soon the hunger grows in you, a deep, dark red thing, and you turn to Keira seeing the same feeling in her eye. Together you rise, and search for prey.