A terrifying nightmare sets off a series of attacks on Deena Bartlett's five senses, and her eighty-year-old Aunt Agatha is responsible. But the old woman is not alone. She's made a monstrous bargain with the Sensu, a malevolent entity whose stock in trade is attacking a person's senses, one by one. It has promised Agatha health in return for one evil act—the killing of her niece.

Deena has remained loyal to her bitter aunt for years—her self-imposed penance for having neglected her now-dead parents. But Agatha is dying and her insults will soon end…until a string of inexplicable incidents. A sound so piercing Deena's nose bleeds. A smell so vile her breathing suffocates. And against all reason, after each attack, her aunt's health improves. With mounting dread, Deena discovers the bargain her aunt has made. When the Sensu thrusts her into its realm, she must battle not only the power of her aunt's long-held secrets but her own guilt as well.