The Ground That Devours Us

The world ended ten years ago.
Vampires showed up, took over, and turned the whole planet into their personal all-you-can-drink buffet. The president? Bloodsucker. The government? Bloodsuckers. My social life? Absolutely nonexistent.
But hey, at least I had one thing going for me—slayer training. My twin sister, Ripley, and I were about to go pro, officially joining the ranks of the last people on earth who actually do something about the whole "undead overlords" situation.
And then X had to show up. The vampire boogeyman. The worst of the worst. And instead of killing Ripley, like any decent monster would, he turned her. Now she's technically a vamp, but something tells me my sister is still in there. Which means I can't slay her.
What can I do? Break every rule. Lie to my friends. Strike a deal with the most dangerous vampire on the planet: X will protect Ripley from everyone else who wants her dead—like, really dead—until I can snag the cure for vampirism. The catch? Risking my own head to help him free his good-for-nothing BFF from the very slayers who taught me everything.
If I want Ripley back, I'm going to have to play nice with the thing that ruined my life. And the worst part?
I think he's enjoying this.