Sally Lockhart (Billie Piper) now runs her own financial consulting business, while her friends Frederick Garland (J.J. Feild) and Jim Taylor (Matt Smith) have opened a detective agency. But when one of her clients loses money over a vanishing steamship, Sally and the young detectives join forces again. The mystery leads them to a threatened stage magician and a medium with a dark vision. Sally must also face an old enemy.