The discovery of Atlantis has led to the British Empire waxing in power in the early 20th century instead of waning. The discovery of power crystals allowed the construction of great monolithic dreadnaughts which rule the skies and waves, enforcing the Empire's will. A British archaeological team exploring Atlantean ruins discover an amazing artefact called the Nucleus which is a massive depository for long forgotten Atlantean knowledge. On investigating an outpost of Atlantis for power crystals, the elite Nightshade Division are attacked by strange deadly creatures and barely get out alive. The British Empire's top agent, John Murdoch joins forces with the elite Nightshade Division's Captain John Riley in a desperate race against time to stop unseen evil forces from launching a deadly attack against the greatest empire the world has ever seen...