The black bird oracle / Deborah Harkness.

Diana and Matthew receive a formal demand from the Congregation: They must test the magic of their seven-year-old twins, Pip and Rebecca. Concerned with their safety and desperate to avoid the same fate that led her parents to spellbind her, Diana decides to forge a different path for her family's future and answers a message from a great-aunt she never knew existed, Gwyneth Proctor, whose invitation simply reads: It's time you came home, Diana. On the hallowed ground of Ravenswood, the Proctor family home, and under the tutelage of Gwyneth, a talented witch grounded in higher magic, a new era begins for Diana: a confrontation with her family's dark past, and a reckoning for her own desire for even greater power - if she can let go, finally, of her fear of wielding it.