The best part of life is flirting with death.
When Riley Dredge is nearly slaughtered by a horrifying paranormal monster, she discovers adrenaline to be the only cure for the oppressive darkness that has blackened her heart since childhood. Immediately becoming addicted to a sensation she calls the Thrill, Riley teams up with the veteran monster hunter who saved her life: Jack, a vulgar, coarse man whose only loves are cash, booze, and his motorcycle. He grudgingly allows Riley to tag along, and together they travel the United States, trading blood for money while learning surprising secrets about each other. Along the way, they'll face the consequences of the past, the danger of the present, and the uncertainty of the future when any day might be their last.