The year is 1878, and Sally Lockhart has started her own financial consulting business. When her client, Miss Walsh, loses a fortune from the unexpected collapse of the Anglo-Baltic shipping line, Sally is determined to find out why so many of their ships have mysteriously vanished without a trace. Hoping to recover the money, she turns for help to her friends, Frederick Garland and Jim Taylor, who have started their own detective agency.
While pursuing the disappearance of the steamship Ingrid Linde, Sally, Frederick and Jim also find themselves investigating stage magician Alistair MacKinnon, who is being threatened by mysterious thugs, and a psychic medium who seems to be tapping into shady business secrets — all of which draws them unwittingly into a dark and sinister plot fueled by the business dealings of the cruel and heartless industrialist Axel Bellmann.
As Sally faces new mysteries and old enemies, she must confront challenges that test her strength and bravery to the breaking point, while Frederick and Jim find themselves in dangerous new company, and a wedding is arranged between an heiress and Bellmann, whose business is built on a horrifying secret.