The game takes place in an alternate reality in 1897, in a technological war between Nikola Tesla, who was a Serbian-American inventor, electrical engineer, mechanical engineer, and futurist, best known for his contributions to the design of the modern alternating current (AC) electricity supply system in reality, and Thomas Edison, who was an American inventor and businessman, described as America's greatest inventor in reality.
While the tale starts on a small boat, the player spends the vast majority of time aboard the Helios, a gigantic retro-styled ocean liner named after the Hellenistic Sun God of the same name and serving as the "haven for the greatest scientific minds". The Helios is the world's largest ship, it chiefly consists of various private quarters and laboratories, furthermore it maintains an internal railway system, gardens, a theatre, a hospital, a cinema and many other facilities, including a Tesla Tower on its uppermost deck. The ship is owned and managed by the fictional company "Wardenclyffe", which is headed by Tesla; the company's name is inspired by that of the real Tesla Tower, officially called "Wardenclyffe Tower". The company is said to supply electricity to half of the world, but desires to supply the other half as well.
Much of the setting is expanded on in various documents, such as letters and newspapers that are scattered throughout the ship; These documents give a brief glimpse of the world the game is set in and some of the events that have taken place. These events include the political tensions between Tesla and various nations who see his massive wealth, ingenuity and resources as a threat along with the struggles that Tesla faces against the numerous spies working for Edison that have arrived on his ship.
Plot
The game begins with Rose Archer arriving at the Helios after receiving a mysterious letter from her sister Ada, who was invited aboard the ship due to her renowned scientific research; The letter is enigmatic with Ada apologizing for leaving Rose quickly and telling her to come to the Helios. Included with the letter is a strange communication device. Rose boards the ship, but is puzzled to see that it appears empty. As she moves into the Lobby, she discovers the word "Quarantine" painted over the doors before they shut her inside.
Rose travels through the ship before being contacted by Ada through the communication device; Ada claims that she did not send any letter to Rose, despite the fact that the letter was in Ada's handwriting. The two sisters decide to try and meet together in Ada's dorm room. While heading to the room, Rose comes across several mutilated bodies of Helios Scientists. Additionally, the words, "Time is not a River" and "The Circle must be Broken" are scrawled everywhere, seemingly in blood. Ada reveals that there was an accident in one the experiments aboard the ship; The exact nature of the accident as well as who caused it, whether it was overconfidence or sabotage, is not explained. Ada only explains that the experiment had to do with Time, the One-Electron Theory, along with the fact that they were drawing the seemingly endless supply of electricity from time itself. While explaining this Ada also theorizes that a future version of herself sent the letter to Rose using the research she was developing on the Helios.
During these events, Rose has begun to see strange ghostly visions of people. These visions seem to be visions of the past; Of people going about their daily business before the accident. Rose also received a communication from a man called Aubrey, who is trapped in the Engine room and requests her help, but Rose only does not hid the fact that she will only help him after finding her sister. Aubrey shows clear signs of mental instability when he reveals that he talks to the dead body of a friend he calls, "Benny".
Ada finds herself trapped in the surgery room within the Biology labs by mysterious means and asks Rose to find one of her research note books which is hidden in Ada's dorm room. Rose finds the notebook, only to then be trapped within the dorm by Tesla who claims to be trying to manage the situation. Rose enlists Aubrey's help to move through the facility as his position within the engine room allows him to access various parts of the ship. In return, she promises to come and save him, after finding Ada. Aubrey agrees to the deal and opens the door for her. As Rose begins to leave the dorms, she comes across a deranged man butchering a scientist while muttering about breaking the circle. Aubrey calls him Ludwig and instructs Rose on how to escape through a nearby rail-station and onto a rail-car. However Ludwig sees Rose and begins to chase her; He shows knowledge of who she is and blames her for the current predicament, despite Rose having no prior knowledge of him. Roses eventually gets away from him.
