Hemlock & Silver T. Kingfisher

Healer Anja regularly drinks poison―not to die, but to save. She is seeking cures for those everyone else has given up on. One day, a summons from the king interrupts her quiet, herb-obsessed life. His daughter, Snow, is dying, and he hopes Anja’s unorthodox methods can save her. Aided by a taciturn guard, a narcissistic cat, and a passion for the scientific method, Anja rushes to treat Snow, but nothing seems to work until she finds a secret world.