The Gentleman Devil. The Ingenious Mechanical Devices, #2

Can death be conquered?When Immanuel Winter set off to the banks of the Thames, he never thought his life would be changed forever. Emmeline Jardine, a young Spiritualist medium, drowns, but the potion given to Immanuel by his mother brings her back from the dead and irrevocably intertwines their souls. But Emmeline and Immanuel aren't the only ones aware of his ancestors' legacy. Understanding the potential of such an elixir, the ruthlessly ambitious Alastair Rose knows securing the mysteries of death will get him everything he desires: power, a title, but more importantly, dominion over the dead and the living.
Unaware of what the dashing madman is capable of, Emmeline follows him deeper into a world of corrupt mediums, unscrupulous scientists, and murder. All that stands between Lord Rose and his prize is the boy who refuses to die, but both men know the key to stopping him lies within the girl who shares Immanuel's soul.