A flicker of envy rushed through Katherine as she gazed up and down the huddled figure of her doppelganger. She wished it was her sitting out there and not Elena. Hell, she would trap both her beloved Salvatore brothers if it meant her freedom from this wretched tomb. She was a mess; the small, black dress she had been wearing for days now was covered in dirt and her hair was hopelessly tangled, but most of all, she was thirsty. She craved fresh blood, not the expired, blood bag poured into a plastic bottle, garbage Elena had given her.
Speaking of Elena, Katherine cocked her head, pretending to ponder the girl's worries, and listened to her heart thud. The girl was scared, no matter how much she denied it. She could lie, even fool, Stefan and Damon, but Katherine knew. She had been in her shoes. She knew what it felt like to have a sadistic hybrid wanna-be chasing after you so you could have your blood spilled over some silly little rock. Blood. As Elena's heartbeat sped, Katherine felt the familiar ache of her fangs penetrating her gums. She knew her face would chagne. She almost turned away, but she controlled herself, and before Elena could even glance up, she returned to normal.
"What's wrong? Afraid I'm right?" Elena appeared to be ignoring her as she brushed a piece of her dreadfully straight hair behind her ear. "Don't wanna die? There's another way out." Katherine deftly slid her fingernail over her wrist, opening a small wound that would have bled more if she had anything in her. Elena looked up, confused and curious, before turning away when she saw what Katherine was suggesting. "Better hurry, your opportunity's going, going, going... and gone." Katherine very obviously feigned disappointment, and Elena glared at her.
Katherine smiled, pretending not to care, but she wanted Elena to accept the blood. Of course, Katherine wouldn't actually allow her to drink, she just wanted the girl to enter her territory for a split second, that's all it would take. Elena wasn't stupid though. She knew Katherine would just trick her into the tomb. Even if Katherine was seriously offering, being a vampire wouldn't solve any of her problems.
Katherine needed to try something else. She suddenly needed Elena in the tomb. Not only did her blood smell delicious, but Elena could be used as leverage to inspire the Salvatore brothers to help her get out of this wretched prison.