Beatrice Scarlet, the apothecary's daughter, returns to 18th century London to solve a murder case steeped in witchcraft. St Mary Magdalene's Refuge for fallen women is supported by a wealthy tobacco merchant who regularly offers the girls steady work. But when seven girls sent to his factory disappear, their would-be benefactor claims they were a coven of witches ... A gripping historical thriller set in 18th-century London.