In an age when the old sorceries have mostly died out, a single unexpected burst of magic upends the lives of three households. Selfish heiress Vespasia Marchand berates an ill woman in the street, a woman who was once a renowned spell-caster. Her granddaughter Melu has inherited her gift, though it has not been nurtured. In a fit of anger, the girl impulsively transforms Vespasia into a wasp, doomed to live out an ordinary wasp's life unless she can sting another person and occupy their body. The shrewd and ambitious Vespasia sets her sights on the queen Callao, a gentle and beloved woman with an adoring husband, King Ranulph, and adored daughter, the princess Linnea. With the soul-theft accomplished, how will Vespasia carry off the charade? How can the king and the young Linnea cope with the sudden awful shift in the queen's character? The heiress's maid Ginevra Hawkeshaw has witnessed the curse; Melu's family flees. The disappearance of Vespasia has set Ginevra free from a lifetime of unhappy servitude, so she isn't sure she wants to help the doughty sheriff Hugh discover what might have happened. And yet, she feels compelled to try to undo the damage. Distrust and trust, love and resistance, ambivalence and dedication, selfishness and generosity, truth and lies, must be navigated to resolve the heartache (with the help of a perspicacious dog).