It is 1882, and from fiery Mercury to the frigid moons of the Outer Planets, a Pax Britannica holds sway. Were it not for Britain's dominance in trade, technology and space travel, Earth's other major colonial powers would wage wars that would consume them all, and end the peace and prosperity that stretches across the Solar System. On Mars, however, an ancient evil stirs in a dead city, dark powers emerging from the dimensions to which they were banished in primal times. As this evil force extends its reach from planet to planet, the ever-precarious balance of power begins to shift, endangering not only Britain's Empire of Steam and Steel, but the entire Solar System and all its inhabited planets. Only a small band of dedicated men and women stand between Civilisation and the Dark Gods of Elder Mars. From a forbidden city in the Martian antarctic wastes to the steaming upland jungles of Venus to the most dangerous quarters of Constantinople and London, they will do whatever they must to fight the shadows rising against the Empire, to serve Queen and Solar System.