In Victorian England, a young woman searches for a priceless ruby and uncovers even greater mysteries.

Sally Lockhart (Billie Piper) attempts to find the meaning behind her late father's last letter which contained the phrase "the seven blessings" - a cryptic message that can strike a man dead with fear. Sally is helped by her friends, including Frederick Garland (J.J. Feild), a photographer, and Jim (Matt Smith), a young assistant at the family's shipping firm. The ever twisting mystery involves assassins, opium dens, Chinese gangs, and the Ruby of Agrapur. The priceless ruby is also sought by the ruthless Mrs. Holland (Dame Julie Walters), who is willing to kill to get her hands on it.—L. Hamre