London, 1882: Queen Victoria appoints Harold Spire of the Metropolitan Police to Special Branch Division Omega. Omega is to secretly investigate paranormal and supernatural events and persons. Spire, a skeptic driven to protect the helpless and see justice done, is the perfect man to lead the department, which employs scholars and scientists, assassins and con men, and a traveling circus. Spire's chief researcher is Rose Everhart, who believes fervently that there is more to the world than can be seen by mortal eyes.

Their first mission: find the Eterna Compound, which grants immortality. Catastrophe destroyed the hidden laboratory in New York City where Eterna was developed, but the Queen is convinced someone escaped—and has a sample of Eterna.

Also searching for Eterna is an American, Clara Templeton, who helped start the project after the assassination of Abraham Lincoln nearly destroyed her nation. Haunted by the ghost of her beloved, she is determined that the Eterna Compound—and the immortality it will convey—will be controlled by the United States, not Great Britain.